Clear-bottom kayak tours

A clear-bottom kayak is an ordinary sit-on-top kayak with a transparent panel in the hull. (For how hard any bio bay kayak tour is and how long you paddle, see kayaking a bio bay.) On a bio bay tour it changes one thing: the glow appears underneath you as well as around your paddle. That is a real difference, and it is available in exactly one place in Puerto Rico.

Where they exist

Mosquito Bay, on Vieques. Nowhere else. Two of the eighteen operators in our register run them, and both are there.

Mosquito Bio Bay Tours sells a tour named, plainly, the Clear-Bottom Mosquito Bay Kayak Tour. From $65 for adults and $60 for children aged 4 to 12, 90 minutes, departing from Calle Flamboyan at 7, 8, 9 and 10 PM.

Black Beard Sports runs clear-bottom kayaks too, from $70 plus tax. Their trip is 2.5 hours door to door with roughly an hour of that on the water, because round-trip transport is included from either their store in Isabel II or the stop across from El Blok Hotel in Esperanza. If you have no car on Vieques, that included ride is the reason to pick them.

Where they do not exist, and what gets said anyway

Laguna Grande, in Fajardo, has none. This matters because Fajardo is the bay most people reach from San Juan, and clear-bottom kayaks get mentioned in connection with it fairly often online. Every Fajardo operator we have checked uses standard sit-upon kayaks, and Puerto Rico Day Trips, a long-running local guide, says the same. If a listing promises you a transparent kayak at Laguna Grande, ask the operator directly before you pay.

La Parguera has clear kayaks, but not on the bio bay. Fondo de Cristal in Lajas sells a Glassbottom Kayak Eco-Tour using what they call 100% clear kayaks. Read the page carefully: it goes out around the cays to look at reefs, in daylight. Their bioluminescent trips are a glass-bottom catamaran, a swim tour, and a boat-plus-kayak combination. The clear kayaks and the glowing water are two different products from the same company.

What the clear bottom actually shows you

Manage the expectation before you book, because this is where people come away disappointed.

The bioluminescence is produced by dinoflagellates that flash when the water around them is disturbed. You see light where something moves: your paddle blade, your hand dragged through the water, a fish crossing under the boat. You do not see a lit-up seafloor through the panel. On a good night the water under a clear hull glows in streaks and swirls as the kayak moves through it. On a bright night it is a dark window.

Which night you get is not luck. It is the moon.

The clear hull costs nothing extra here

This surprised us, so it is worth stating plainly. At Mosquito Bay the clear-bottom tours are not a premium product. Mosquito Bio Bay Tours is $65 and Black Beard is $70, while Abe’s Snorkeling, running standard kayaks on the same bay, is also $70. The cheapest tour at Mosquito Bay is a clear-bottom one.

So there is no upsell to weigh. If you are going to Vieques and you want a kayak, the transparent hull is available at the same price or less, and the only real choice between the two operators is whether you need the included transport.

Book it against the moon, and against the closure

Mosquito Bay is the brightest of Puerto Rico’s three bays, and it is also the only one with a hard legal closure. Puerto Rico’s Department of Natural and Environmental Resources closes it to tours on the night before, the night of, and the night after every full moon. Three nights a month there is no tour to book, not a poor one.

Aim for the new moon, and check the moon calendar against your dates before you book flights, not after. This is the single decision that most affects what you see, and it costs nothing to get right.

Two things a clear hull will not change

You cannot swim. Swimming is banned at Mosquito Bay outright, so the water stays on the other side of the panel. If getting into the glow is the point of the trip for you, La Parguera is the only bay in Puerto Rico where that is allowed, and no clear-bottom kayak tour runs there.

You still have to get to Vieques. Mosquito Bay is on a separate island reached by ferry from Ceiba or by a short flight, and tours run after dark, so realistically it means staying the night. Our guide to getting to Vieques covers the ferry and the flights.

If that trip does not fit your week, Laguna Grande in Fajardo is about 45 minutes from San Juan and works as a single evening, in a standard kayak. A standard kayak on a new moon beats a clear-bottom kayak on a bright one, every time.