Yucab Reef

The first minutes have no reef in them. Boats drop at the southern end onto sand and flats of turtle grass, and that is deliberate, because the grass is where the small animals are and a guide who knows the site slows the group down over it. Stingrays lie in it. Pufferfish hang above it. Somewhere in there, if the guide finds one, is a seahorse.

Then the reef assembles. Coral heads three to six metres tall stand out of the sand with channels between them, hung with barrel and tube sponges, and the drift takes you north into the body of the strip. The patch you land on at the southern end is thick with spiny lobster. Work outwards and you reach the seaward edge, where a ledge runs with an overhang under it. That overhang is the piece of this dive experienced Cozumel divers single out. It breaks the current, so it is the one place on a drift where you can stop and look at something properly, and what is under it is lobster and sleeping nurse sharks, described here at two metres and more.

Somewhere in the second half a small swim-through opens out onto sand. Guides who work the reef string several of them together. The reef is dived on more than one line, so a second visit in the same week can come at the same ground from the other side and turn up what the first pass missed.

How the dive ends is decided by the water. Tormentos is the next reef north, and when the drift is running and gas allows, boats let the dive carry on into it.

The splendid toadfish is the reason to choose this reef over the two either side of it. It is a fish of dens under coral heads at the sand and rubble line, normally between eight and twenty-five metres, which puts Yucab's whole profile inside its window. Divers keep reporting them here, including a Cozumel resident confirming another visitor's set of photographs. It is IUCN Endangered, it is not endemic to Cozumel the way half the island's copy claims, but it is found almost nowhere else and reliably only here. By day you generally see the face and nothing more.

Then there is a swim-through on a reef that has no business having one. Three separate divers describe the same feature, one of them precisely enough to locate it: a small passage in the second half of the dive that opens out to sand.

The third thing is time. At twelve to eighteen metres the constraint is gas, and decompression never enters it, which is unusual on an island that sells wall diving, and it changes the character of the dive. You look at things until the tank says stop.

Yucab is not universally loved and the dissent is specific. One repeat visitor calls it a pretty reef but not exciting, with nice sponges and a few lobsters hiding about. Another remembered it as thin on fish and then found it healthier than before. Both readings are true of the same reef on different days, and between them they describe the reef as it actually is: a site whose quality turns on the current and on how many other boats are working it. Nothing here is dramatic. Everything rewards looking closely.

Twelve metres of clear Caribbean water puts real light on a subject, and that is most of why photographers keep coming back to a reef nobody calls dramatic. The two shots are the turtle grass at the start, which is macro work on seahorses, pufferfish and rays over open ground, and the overhang on the seaward edge, which gives you the one sheltered spot on a drift where you can hold a position long enough to compose.

The toadfish is the picture everyone wants. It also comes with rules. Look along the seaward side of the reef, at small openings near the base of the coral where it meets sand, and move slowly. Divers have watched a guide bait one out of its den and describe it as the worst thing they saw underwater on the trip. Coaxing an animal out of its refuge is prohibited in this park, and so is grabbing the coral to get a lens into the hole. The reef that shelters the fish is worth more than the frame.

You do not pick Yucab. The boat does, and the choice is settled by consensus among the divers aboard, by which reefs are open that week and by the day's conditions. What follows from that is the single most useful thing to know here: you will not have the reef to yourself. This is the site the fleet uses to fill the second half of the morning, groups meet on it, and divers report both crowding underwater and heavy boat traffic on the way up.

Tank size is worth specifying when you book. This dive is limited by the gas you carry and by nothing else, and the difference between a standard fill and a big one is the difference between forty-five minutes and seventy. Nitrox is worth it on the same logic and is charged as an extra.

Which reefs are open is not fixed. The park closes complexes in rotation to let them recover from coral disease, three at a time out of fourteen1, and no calendar for the year is published anywhere. The answer comes from the shop, on the morning, and it is a better question than asking for a named site.

The rest is the park's baseline and it applies from the moment you go in. A guide has to be in the water with you and will check your buoyancy first. Stay a metre and a half off the coral. Gloves and knives are not allowed, which means buoyancy is the only way you have of keeping off a reef whose whole interest is at the base of the structure.