Atlantis Submarine Expedition

The Atlantis Submarine Expedition takes you beneath the surface of Grand Cayman's marine park in a passenger submarine, dry, seated and with a large window beside you. Guests meet at the Atlantis Adventure Center on the George Town waterfront, take a short boat transfer out to the submarine and then spend about forty-five minutes descending along a wall to roughly a hundred feet. The cruise passes barrel sponges, star corals and schools of snapper and grouper, with the occasional stingray or turtle, while a guide narrates. The whole outing runs around an hour and a half. It is one of the few ways to see the reef at depth if you are not a certified diver, and it suits nervous swimmers, older travellers and families.

What you see depends on the day, but the pattern is consistent. The submarine drops down the face of the reef wall, where sponges and corals are the architecture and fish gather around them. Snapper and grouper are common, and visitors have reported barracuda, lionfish, spiny lobster, the odd nurse shark and a shipwreck on the route. A night option exists in which lights pick out the nocturnal hunters, so ask when you reserve. Seating is by the windows and the cabin is air-conditioned, which is a relief on a hot afternoon.

Practical points matter more than usual. Children must be at least 36 inches (92 centimetres) tall, and the experience is not recommended for very young children. Guests need to be able to manage about ten steps in and out of the submarine, though wheelchair users who can stand for the transfer have taken part. You usually confirm your departure time after booking rather than choosing it, with slots given on a first-come basis, and free cancellation applies up to a day before.

Rough weather can cancel a departure, so keep the day flexible and avoid scheduling it just before a flight. The operator's inclusions vary, so check what your ticket covers, including transfers and drinks.

It works best as a counterpoint to the snorkel trips. If you have already floated over the Kittiwake or stood on the sandbar, the submarine shows a completely different depth zone, and it is a good option for anyone who cannot or will not snorkel. It is also a calm choice for a cruise day in George Town.

Bring a light layer, since the cabin can feel cool, and a camera that handles glass reflections; keep flash off. Confirm that the current schedule is running before you plan around it, because the operation is weather dependent.

To get the most from the outing, sit near a window on the side the pilot indicates and keep your eyes on the edge of the wall, where fish gather and the best sightlines open up. Listen for the guide's commentary about the marine park, since protected status explains why the reef looks healthier in places than visitors expect. If you tend to feel closed in, tell the crew before boarding and choose a seat near the aisle.

Pack light, because bags are awkward in a small cabin, and leave large camera rigs behind in favour of a phone or compact camera. A morning departure usually gives the calmest sea for the boat transfer. Finish with a walk along the waterfront and an early lunch while the experience is fresh.