Back in Maui and I cannot wait for my first Scalloped HammerheadShark dive off of Molokai. We come back here each year for this dive and it is one of my favorite dives on the planet. The rich biodiversity of this dive site, the great topography and of course, the Scalloped Hammerheads.
Scalloped Hammerhead Shark, Sphyrna lewini, Molokai Hawaii, Mokuho’oniki Rock
I have been diving on this site now for over 10 years and it never gets old. It is an advanced dive and the seas can be quite rough but oh, what a dive. If you get the chance to dive here, I highly recommend it.
I dive the site with Lahaina Divers, which is the only dive operator on Maui that goes to this site. Lahaina Divers is a great dive company, extremely professional and competent with a number of diver professionals that have been on Maui for a number of years.
Mokuhooniki rock is situated off the northeastern point of Molokai in the Pailolo Channel. The trip takes about an hour from of Lahaina Harbor. You do a two-tank dive on the site with a surface interval of about 45 minutes. I dive this on Nitrox to help with bottom time, especially given the short surface interval. This will also allow you to descend to depth when needed for that perfect shot. The dive site ranges from 60 to 110 feet although at the end of the dive you could be in water that is over 150 feet.
The Scalloped Hammerhead Shark, Sphyrna lewini is an amazing creature. The adult can reach up to 14 feet in length but those found around Mokuhooniki rock tend to be around 6 to 10 feet in length. They typically can be found swimming alone or in small groups of 2 and 3s. However, there are times when these sharks begin to gather especially towards the summer where you can see dozens swimming together on this site.
Interaction – Scalloped Hammerhead Shark, Sphyrna lewini, Molokai Hawaii
shark with their GoPro hoping for that amazing shot. The result, of this behavior, is the shark will turn and swim away and deny the rest of the dive group a chance to interact with the shark. The best way to observe most sharks is to stay still or move slowly. The Scalloped Hammerhead is curious and if your dive group is still and chill you may well get an encounter you will never forget. I have had these marvelous sharks circle me for over 7 minutes on on a dive. But again, your group typically needs to be very relaxed to be able to get these sharks interact with you and the rest of your dive buddies.
I like to stay around 60 to 65 feet and look into the blue to spot the sharks. When I see some that are close or look like they may come in close I slowly descend to their depth, typically about 80 to 90 feet. However, these sharks can be anywhere in the water column so make sure you keep your head on a swivel. I like to stay on the outside of the dive group and towards Molokai on this dive. Typically, I stay about 10 meters away from Dive Master. This position allows me to better interact with the sharks without worrying as much about other divers behavior. However, you will encounter sharks close to Mokuho’oniki Rock and in the middle of the channel. So don’t worry, just keep looking and watching your dive guide.
This is amazing dive site. Take your time and enjoy.
A south swell has been running for several days with the wind blowing briskly out of the north. It is Friday morning and I am looking forward to scuba diving with the Hammerhead Shark. The dive site for today is about an hour from Lahaina Harbor across the Pailolo Channel and on the northeastern end of Molokai. This dive will take approximately five hours from the time we leave the harbor until our return.
I checked into the Lahaina Divers shop, whom I highly recommend, around 6:50 am. I have been diving with them in Maui for over 10 years. They have great boats and a skilled and highly professional crew. Lahaina Divers is the only dive operation that has a regular Hammerhead Shark dive to Molokai. After checking in, I park my car and then head down to the boat slip. After all of the divers are aboard and a short safety briefing from the crew we head for Molokai. A
Scalloped Hammerhead Shark – Encounter with 12 foot female
few of the divers on board have done this dive, including myself, many times. However, for most on board this will be their fist dive on Molokai and the first time with Hammerhead sharks.
The boat heads toward the dive site, staying close to the western shore of Maui, until we are almost directly across from the dive site. The boat then makes a sharp turn to cross the channel. The seas are running four to six feet with an occasional swell in excess of eight feet. Some first timers on the boat get a bit nervous. It takes about 25 to 30 minutes to cross over to Molokai and by that time a couple of divers on the boat that are sea sick. This channel is one of the roughest in the Hawaiian islands. Its name literally means “crazy fishermen”. Because if someone was going to go fishing across this channel they must be crazy.
Scalloped Hammerhead Shark – Exploration
The captain of the boat gives us a 10 minute warning telling us it is time to put on our gear and get ready to enter the water. We put on our wet suits, BC’s, and fins while sitting in assigned stations on the boat. The water is rough so we wait on the crew to help us stand up and move into position at the back of the boat. But, we don’t enter yet. We wait for the captain to move the boat into position and give us the signal to enter the water. The crew tells us “1 minute”, “30 seconds”, “captain divers are ready”, then we wait for the captain. The back of the boat swings round toward the islet, then the captain yells “dive, dive, dive”. Our group jumps almost in unison and we are all in the water within 15 seconds.
The surface is choppy and after making sure all divers are OK, we rapidly begin our descent. The water is light to medium blue for the first thirty to forty feet with rays of sunlight filtering around us. Then the water begins to slowly darken as we descend on the dive site know as Fish Rain. The reef is on our right and blue water is to the left. The bottom slopes gently downward from about 40 feet to around 120 feet. While I love the reef, I constantly look into the blue, hoping to see a Scalloped Hammerhead Shark.
Fish Rain is located on Mokuhooniki Rock and is one of the most bio-diverse dive sites on the planet. The density of marine species, the health of the corals and the presence of pelagics make this a must dive. But, again we have come to see the Hammerhead Shark.
Scalloped Hammerhead Shark Close Up
The dive starts out in the lee of the islet which is somewhat protected from the crazy waters of the Pailolo Channel. While this site can on rare occasion be like glass, it most often has swells of 2 to 4 feet and can grow on occasion to well over 6 feet. This is not a dive for the novice diver. This is an advanced dive and anyone thinking about going should carefully consider their level of experience and confidence.
You enter the water quickly from a moving boat a quickly descend to around 50 feet. After your dive group assembles you will slowly make you way around the Islet in an arc. The dive is a drift dive and can be one of the most difficult dives you will every make due to the entry into and exit from the water. Again this dive is not for the novice, but oh what a dive. I have been on this site dozens and dozens of times yet it never ceases to amaze me.
Scalloped Hammerhead Shark
Scalloped Hammerhead Shark In Close
The Scalloped Hammerhead (Sphyrna lewini) is a species of hammerhead shark, and part of the family Sphyrnidae. This shark can be found over continental and insular shelves and in nearby deeper water. It is found in warm temperate and tropical waters, worldwide from 46°N to 36°S. It can be found down to depths over 500 m (1,600 ft), but is most often found above 25 m (82 ft). During the day, they are more often found close to shore, and at night, they hunt further offshore. Adults are found alone, in pairs, or in small schools, while young sharks occur in larger schools. see this Wikipedia article for more details on Scalloped Hammerhead Sharks
The Scalloped Hammerhead Shark in Hawaii has been known to reach lengths of up to 13 feet however 6-8 feet is typically the average. Near Mokuhooniki Rock, the Scalloped Hammerheads tend to be adults of 6 to 8 feet with the occasional shark measuring well over 10 feet. These sharks can be found from very near the surface to about 130 ft. We see them very often cruising just off the bottom of the channel between Molokai and Mokuhooniki Rock, where the depths run typically 100 to 130 feet. We will see them in groups of 1 to 3 but many times you can see groups of 5 to 10 and occasionally many more. On my best dive here I have just under 50 Scalloped Hammerheads and have been literally surrounded as I am taking photographs.
Observing Scalloped Hammerhead Sharks
These are magnificent creatures. It is a wonderful experience to remain absolutely still in the water and observe these sharks as they interact with you. I have have had many occasions where sharks have swam with me for 10 to 15 minutes. They are curious and will come in close to you and your group if you will remember a few key things:
Keep your head on a swivel as you dive. You want to be able to spot the sharks as soon as possible so your behavior does not cause them to move away from you
When you see the sharks and you see they are heading in the general direction of your group slow down immediately and/or stop and observe their behavior
If the sharks are moving away from your group keep swimming toward them and keep looking all around. There are more than likely other sharks near by.
Stay at 40 to 60 feet when you are looking for the sharks and then drop down to their depth when you see them. This will conserve air and reduce the danger of nitrogen narcosis
When the sharks are getting close to you stay still and let them swim to you. I was getting ready for a wonderful encounter with a 12+foot female Scalloped Hammerhead Shark when a person in our dive group start swimming rapidly down towards the shark to get their “go-pro” shot. The shark simply turned away and the diver probably did not get a good shot and the rest of the dive group was denied the experience of interacting with a large hammerhead.
The Pool Is Open
As I have said before, if not my very favorite, definitely in my top five. This site has an amazing reef, tremendous bio-diversity, a very healthy reef system, does not see many divers and it has ….. Scalloped Hammerhead Sharks.
If you are an advanced diver, this site is definitely for you. Maholo nui loa and safe diving.
Knob Hill is an interesting and very nice dive site. It is fairly shallow about 55 to 60 feet (16 to 18 meters) and teeming with life. However, it is often not possible to dive on this site due to strong currents . The dive site is just off the coast of Lanai by the Four Seasons Hotel. The name comes from a large rock formation near the surface that is supported by four columns. This is a large dive site on the south side of Lanai that is quite exposed. I have been diving around Lanai for over 12 years and have been on this site maybe three or four times.
Knob Hill Rating = 3.86 out of 5
Visibility – moderate to very good
Access – Moderate; boat only and 45 to 50 minutes from Lahaina Harbor
Current – moderate strong most of time
Depth to 60 ft / 18 m
Reef health Hard / Soft Corals – Very Good
Marine species variety – Very Good
Pelagics / Mammals / Turtles / Rays – moderate to good, typical at least 1 to 3 sightings up close, sometimes many more
The only reason this site is not rated higher, is the current makes it a very difficult dive site to dive 80% of the time. If the current is mild this is an awesome site.
Knob Hill Overview
Knob Hill Reef
Knob Hill has a number of swim throughs and volcanic structures, such as the “table” above that make the site quite interesting. The marine life on the site is varied and abundant. You will almost always find large schools of Pennant Butterflyfishes along with a wide variety of other Butterflyfishes, Dascyllus, Yellow Tangs, Sea Turtles, White-tip Reef Sharks, various eels and much more. Once the boat is on the mooring at Knob Hill, the dive master make take you on several different routes around this expansive dive site. The hard coral here is quite healthy due to the current and infrequent visits by divers. There is a nice swim through / cave where you can frequently find White-tip Reef Sharks. You can also see quite a few nudibranchs on this site and rare species such as the endemic Yellow-striped Coris and Reticulated Butterflyfish.
White-tip Reef Shark, Profile, Triaenodon obesus, (Rüppell, 1837), mano lalakea, Lanai, Hawaii
There is also a nice swim through / cave on the site where you can many times find White-tip Reef Sharks. This shark in particular was quite curious and swam with me through the swim through. He even gave me a nice profile. 🙂
Scuba Diving Molokai can be awesome, especially at Mokuhooniki Rock. The reef here is one of the most interesting that I have dove on anywhere on the planet. The variety of marine species, the isolation and the relatively untouched environment make this a one of a kind location. But……we all come for the Hammerheads.
Mokuhooniiki Rock, Molokai
Mokuhooniki Rock or islet is located at 21 07′ 40″N, 156 42’20″W just off the North eastern coast of the island of Molokai. This dive site, also known as Fish Rain, is one of my top ten scuba diving sites in the world.
Interacting with such a variety of marine life combined with the opportunity to spend time with large pelagic species makes this a special place. When scuba diving Molokai Mokuhooniki Rock, you encounter Hammerhead sharks on almost every dive. You will also see a rich and diverse ecosystem containing large schools of Damsels and Butterflyfish to Dolphins, to Tiger Sharks and much much more. You will be hard pressed to find other dive sites that have the abundance and variety of marine life in such a pristine condition. If you are on Maui and you are an advanced diver, you simply must do this dive.
Scuba Diving Molokai – The Adventure
Spinner Dolphins Molokai Hawaii
This site can be adventure diving at its peak. It takes about 45 minutes to an hour to go from the harbor in Lahaina to Mokuhooniiki Rock. Crossing the Pailolo (means crazy fishermen) channel alone can bring seasoned divers to their knees. It can be quite rough. This is not a beginners dive site. In fact even if you are an advanced rated diver, you should be extremely comfortable exiting a moving boat and reentering a moving boat in potentially rough and choppy seas. I have been on this site dozens of times and while it can be like glass, it is extremely rare. The site can also have 6+ foot waves. I have seen divers break ribs on their reentry and others become extremely agitated and near panic on the pick up. I remember one dive in particular where the waves, even in the lee of the rock, were running about 8 to 10 feet. As the boat came around to pick us up I was literally on the top of one wave looking down at the captain of the boat who was on the top deck of a double deck dive boat. The boat was some 5 feet or so below me in the trough of a wave. I was thinking this is going to be a very interesting pickup.
But……what a great scuba diving site.
When scuba diving Molokai at Mokuhooniiki Rock, you enter the dive site typically in the lee of the islet on the right above. The
Scalloped Hammerhead Shark, Sphyrna lewini, Molokai Hawaii, Moku Ho’oniki Rock
crew will let you know about ten minutes before it is time to enter the water. They will begin lining you up at the back of the boat one at a time. You will have your mask and fins on, BC inflated and be holding anything you want to take into the water with you, including cameras. If you have not entered a dive site from a moving boat before this will a bit of an adventure for you. Think of it as channeling your inner Navy Seal. When you are lined up at the back of the boat, the captain will swing the boat around toward the islet and when all divers are ready, the crew will say Divers Ready. They will then begin counting down two minutes, one minute, etc. Then when the Captain gives his ok the crew will give you a signal “Dive, Dive, Dive”. Do NOT enter the water before the crew has given you the OK, and said “Dive, Dive, Dive”. The divers will quickly enter the water one after the other as the boat is moving. Typically up to 8 divers may enter in 15 to 20 seconds. You will then meet you dive guide on the surface and all begin your descent together. You are usually on the surface no more than 30 seconds before beginning your descent.
And what a wonderful descent. The islet will be on one side and you will see a gradual slope towards the bottom beneath you. The
Fish Rain, Molokai Hawaii
depth is about 100 to 110 feet in the channel but only about 50 to 60 where you will be dropped off. The visibility is usually very good allowing you to see 100 to 150+ feet in the distance. There are fish everywhere.
The dive itself is basically a half-circle around Mokuhooniiki Rock and the boat will pick you up on the other side. Dive time is usually about 50 minutes give or take depending on depth of the dive and your air consumption. If you dive Nitrox, this is a great spot to use it as you can get a little more time at depth when looking for the Hammerheads. I usually hang out to the left of the group as I don’t want to have a lot of other divers close to me when I am trying to get a shot.
The Hammerheads sharks are a bit skittish. If you or someone in your group swims rapidly towards them, they will simply move away. The key is to go slow and easy and be patient. As you start your descent from the boat you will follow the slope down to around 50 feet and then do one of two things. Either start swimming out into the blue and looking for the sharks, which we do many times on the first dive, or you will begin to swim around the islet.
There can be a bit of current here but usually it is not too bad. Or if there is a ripping current it is usually going the direction of the dive once you pass the corner of the islet and it simply becomes a drift dive. When Scuba Diving Molokai, you can see anything from dolphin, to Tiger Sharks (not often), to Greys, to Hammerheads, to a Monk seal. You may also encounter a variety of rays and there have even been a few rare Humpback Whale sightings while on the dive (December to April). The abundance of various fishes and eels will blow you away. There are also many endemic species on this site so be attentive and take your time.
When you surface you will stay with your dive group until the boat comes to get you. You will need a safety sausage to go on this dive and at least one of you will inflate the sausage at the end of the dive to signal the boat. If it is rough it is very important to stay as close together as possible while you are waiting to be picked up. Their could be one or max two other groups in the water, so you may have to wait several minutes to be picked up. Again be patient.
The boat will come very close to you and throw a line out to the divers. You have to swim to the line and grab a hold and then begin to slowly move up the line towards the boat. You will take off your fins while you are holding on the line and have those in one hand to give to one of the crew as they help you aboard. If you have a camera as I do, then you will give them your camera first to the crew and then take off your fins. Then you will proceed towards the boat and use a ladder to board. This can be quite intimidating if you have never done something like this, but the crew is exceptionally good at what they do. Listen to them and do as they say and you will be fine. Believe me this dive will be worth it.
After you finish your first dive and complete your surface interval, you will basically repeat the same dive on your second dive. But there is enough on this dive site to interest you no matter how many times you dive it.
After scuba diving Molokai you get to relax on the boat ride back to Lahaina and enjoy the other adventures that Maui has to offer.
Scuba Diving Lighthouse is always a treat. It is located off the island of Lanai which provides some of the better dive sites in Maui County. Lighthouse is a great dive site that is not visited often due to the distance from Maui. I dive this site with Lahaina Divers, my favorite dive shop on Maui, usually on a drift dive charter that runs each Thursday. Check out Lahaina Divers, dive schedule for more information.
It is about an hour around to this site from Lahaina Harbor and it is usually a nice boat ride, but the channel between Maui and Lanai can be rough so if you are prone to sea sickness, make sure to take Bonine, ginger, use the patch, etc., before you get on the boat.
Scuba Diving Lighthouse
Lighthouse Rating: 3.11 out of 5
This scuba diving site gets its name from a structure on shore that resembles a small lighthouse. The site has a number of large boulders strewn around the bottom and has a wide variety of marine life. This scuba diving site can get blown out by wind and current and be very cloudy. However, the boat captain and dive master will check out the conditions prior to getting in the water. The conditions today were great. The sea was very flat, the current was quite mild and the visibility was 100+ feet.
Scuba Diving Lighthouse: What You Will See
You can typically see smaller White-tip Reef Sharks, a wide variety of butterfly fishes, Triggerfishes and much more. Make sure you check in the cracks and crevices where you can find octopus, a wide variety of eels, crabs, shrimps and other small marine life. The hard corals here are also in good shape as they get a lot of nutrient and not many divers on the site.
Scuba Diving Lighthouse is a treat if you are going to be on the Maui for a few days. I usually dive on Lanai two or three times during each trip and Lighthouse is often the second dive on Lahiana Divers’ Lanai drift dive.
Ahhh… Hawaii. Back on the island of Maui and looking forward to some great diving.
Light From Above
The day began with a short ride over to the island of Lanai for our first dive at First Cathedrals.
I am diving with Lahaina Divers, my favorite dive operator on the island. I have been diving with them for almost 10 years and they are a great choice for scuba diving Lanai.
First Cathedrals is a lava tube that rises to the surface of the ocean. As the name implies there is a large underwater dome inside the lava tube with a number of openings where light shines down into the “cathedral area”.
This is one of the most popular sites for scuba diving Lanai and even though I have been on the site dozens of times, I still thoroughly enjoy the dive.
The entrance into the lava tube looks small and dark, but the interior is quite large. The “cathedral” measures approximately 60 feet in length and the height varies from 10 feet to 40 feet.
Scuba Diving Lanai: Inside the Lava Tube
Scuba Diving Lanai
If you have ever been to a church or cathedral with stained glass windows, you probably noticed the light shining through the glass as you entered the chapel or sanctuary. This dive site gets its name from a similar effect caused by the light shining in through the holes in the lava tube, e.g, the stain glass windows.
Another interesting feature of this dive site is the exit from the lava tube. It is fondly know as the “shotgun”, because when you exit, the surge may “shoot” you out of the cathedral as you surf the pressure wave. If the wave action is strong, it reminds me of what it must feel like to be “flushed”. But don’t worry; the exit is wide and I go through it with my camera with no problems.
Into the Light
If you are concerned about exiting this way, just let your dive master know and you can exit via the way you came in and just circle around the pinnacle to meet up with your group. This site also has several other interesting lava formations off the main lava tube and a variety of marine life.
First Cathedrals has been the site for numerous underwater weddings and proposals and it is a great place for underwater photography. To get the best photographs, it is important that everyone going into the “cathedral” is careful not to stir up the bottom or you will get a lot of backscatter in your photos.
In order to get the best lighting effects, I check the forecast to see when it is going to be sunny and then compare that to the Lahaina Divers’ schedule. You can get the best photos when it is sunny and you can see rays of light coming through the holes in the lava tube and shining down inside.
Molokini Crater is one of the best dives if not the best dive on Maui. This scuba diving site is only accessible via boat and is at the remnants of an extinct volcano. The crescent of the volcano “cone” rises above the sea some 165 feet. The small island lies in the Alalakeiki Channel between the islands of Kahoolawe and Maui. The opening side of the crater faces the northwest and only a short boat ride from the Wailea side of Maui. If you are interested in some of the history around Molokini Crater there is a short article written by Edward L Caum, Geology of Molokini and published in 1930. There are a couple of “plate” photographs included in the article and it is interesting to compare to the crater today. Molokini Crater has been a Marine Preserve(MLCD) since the summer of 1977 and features one of the most pristine hard coral reefs in Hawaii.
The ride from the Lahina side of the island takes about 45 minutes and if you tend to get sea sick, I would recommend driving about 45 minutes or an hour to the Wailea area where you can take a very easy boat ride to the crater.
I prefer scuba diving with Lahina Divers but you must take about a 45 minute boat ride to the Molokini crater. If you want you can use a scuba diving operator that leaves from the Wailea side of Maui. If you are staying in Wailea I would certainly recommend this, although the boats tend to be smaller and there is one operator on that side that I simply refer to as the “Scuba Nazi”. So be careful of the operator that you choose. Make sure you check out the reviews and the equipment used by each of the dive operators. The v-hull boats that leave the Wailea area can be quite cramped if the number of divers is more than 10 on the boat and on many of these there is little if any room to move around.
Access – Moderate to Moderately Difficult to reach the site; boat only (You should not take a boat from Lahaina if you get seasick – 45 minute boat ride); Much easier ride from Wailea side.
Depth to 125+ft
Visibility – good to excellent
Current – mild to extremely strong at the edges of the crater
Marine Species variety – good; normally White-tip Reef Sharks at about 110 feet on the far eastern edge of the crescent
Reef health – good to very good
Scuba Diving Molokini Crater is certainly the best boat dive on the island of Maui. You have to go to Lanai or Molokai to find better deep water scuba diving sites. The clarity of the water is usually quite good at Molokini and there are a several dive sites on the volcano on the outside of the crescent shape crater and on the inside of the crater.
Enenue – Inside eastern tip of the crescent
Middle Reef – Inside just to the east of the middle of the crescent and closer to the cone
Tako Flats – Inside on the western side of the crescent
Reef’s End – Far western end of the crescent
The Back Side – Outside or on the back of the crescent
For inside the crater I like the Eastern edge – Enenue. At about 120 feet there is a series of overhangs that tend to house several White-tip Reef Sharks. As you are swimming down and back up after visiting the “condos” there is a good variety of marine species. You will find typical butterflyfishes, wrasses, damselfishes, eels, and crustaceans all around the crater. You will also find sea turtles on a regular basis and on a very rare occasion humpback whales have been seen by scuba divers at Molokini crater.
The current can be quite strong on the outside edges of the crater, so do not go outside the crater for any reason if your group is scuba diving the “inside”. The current at the edges can take a diver quite a distance in a very short period of time. For this reason you must take a safety sausage with you on this dive and know how to use it. If you are scuba diving the inside of the crater you will rarely have much if any current and even if the seas are choppy the cone of the volcano protects the inner dive sites quite well.
In the sand flats of the crater you will often find Freckled Snake Eels, so take your time on this dive and also make sure you “look” into the distance often as you can see various types of sharks and on especially amazing dives you may even see a Humpback Whale. If you are diving in whale season (December to April/May) make sure you listen for the whale song. In February to early April I have heard literally dozens of whales singing to each other. It certainly makes the dive a lot more interesting.
First Cathedral is one of the most visited scuba diving sites on Lanai and in Maui County. It is a dual pinnacle site and is also one of the largest scuba diving sites in Maui County.
The mooring at the pinnacle is about 35 feet deep on the shallow portion and has a large arch on the west side. The northern side of the site has a wall with lava caves, crevices to explore and a swim through arch. A sand channel separates this from the wash rock pinnacle that comprises First Cathedral. The large cavern, of the Cathedral, has a maximum depth of 45’-50’ deep and a ceiling overhead which is approximately 20’ high. It has a lace work of openings in the lava on the east wall that allows light to flow inside. These openings seem very much like stained glass windows within a church or cathedral.
When you enter the water on the mooring you you will swim first toward the Pinnacle containing the lava tube known as First Cathedral. Then after exploring the “Chapel” as I like to call it, you exit rather quickly, or as some like to say, you are flushed from inside First Cathedral to reef outside. There is an opening on the inside of the Cathedral which has water rushing in and out with the actions of the waves. You swim to the exit “portal” and then hold on as the water rushes into First Cathedral and then when the flow reverses you enter the portal and are rather quickly deposited on the outside of the reef. This is not as intimidating as it might first seem as the opening is fairly large and you only travel a short distance before exiting on the reef. That said, if you have a camera, please bring the strobes in before entering the portal and you should not have any trouble. If this is too much excitement you can exit the Cathedral the same way you entered and simply swim around to the other side.
First Cathedral is an ancient lava tube that has several openings on the upper portion and side of the cavern. These openings allow light to pass through them and provide some great opportunities for underwater photography. I especially like black and white images of the cathedral as they seem to provide the most dramatic effects with the light. The ceiling “window” provides very good lighting (assuming sunny skies) on a rocky outcrop in the middle of the room and you can see “rays of light” shining in from the top of the dome making for some interesting underwater photography. The opening to enter the cathedral is very large and should not cause anyone concern. First Cathedral can hold many scuba divers at one time but I find it best, especially when trying to take photographs, to be in a small group or be first. Having a larger number of divers will stir up a good bit of sediment making it especially difficult to take good shots. It is also better to be in “group 1” verses “group 2” if you have a large number of divers on the boat as the silt in the Cathedral will tend to get stirred up as more divers are going through the cavern.
Once inside First Cathedral, you will find a number of different fish species and more than likely a school of Brick Soldierfish up towards the ceiling. When you exit the cavern you will be on a portion of the reef that usually has a nice diversity of marine life. You will head towards a swim through where you will find a number of different butterflyfishes, moray eels, frogfishes, nudibranches, goatfishes, and much more.
There are several archways to swim thru and the coral gardens are great places to look for eels, shrimps, and small crustaceans. So take your time on this site and you will be well rewarded.