Glass bottom boat tours

People search for this constantly, and most of the answers online are wrong in one direction or the other. Here is the short version: one glass-bottom boat bio bay tour exists in Puerto Rico, it is at La Parguera, and at $22 it is the cheapest of the eighteen tours in our register.

The one that exists

Fondo de Cristal operates out of La Parguera in Lajas. Their bio bay trip runs on a two-level catamaran with glass viewing panels set into the lower deck, which is where the name comes from: fondo de cristal is Spanish for glass bottom.

$22 per person, one hour, all ages. Departures at 7:30, 8:30, 9:30 and 10:30 PM from the pier next to El Karacol. The boat runs about 20 minutes out to the bay, and you watch the water light up around and beneath the hull through the viewing panels.

Two practical notes. When we checked their booking system, only the 7:30 PM departure could be reserved online; the later three read “Call to book” at 787-899-5891. And their own website publishes no price at all, so the $22 above comes from their live booking system rather than their price list.

What the other two bays have instead

Mosquito Bay, Vieques: no glass-bottom boat. The closest thing is a clear-bottom kayak, which two operators run there, or an electric boat if you would rather not paddle at all. Isla Nena Biobay Boat Tours runs a 24-foot electric catamaran, 40 minutes, from $85 plus a $3 cash park fee, departing from the Sun Bay Beach entrance. No glass in the hull, but no paddle either.

Laguna Grande, Fajardo: no glass-bottom boat, but there is a boat. Laguna Grande is reached through a narrow mangrove channel, and most tours go in by kayak. One operator we list, BioIsland, runs an electric boat into the lagoon, 1 hour 15 minutes from $69. It is not glass-bottomed. We wrote here until October 2026 that Fajardo had no boat of any kind; that was wrong.

If what you actually want is “no paddling”

A lot of people searching for a glass bottom boat are really asking a simpler question: can I see this without kayaking? Yes, at two of the three bays, and the glass is not the deciding factor.

At La Parguera, besides Fondo de Cristal, Paradise Scuba runs a two-hour boat trip at $70 that includes about 30 minutes swimming in the bay, Torres Boat Rental runs an hour for $40, and Aleli Tours and Hook’d on Adventure both run motorboat trips. La Parguera is also the only one of the three bays where you are allowed in the water.

At Mosquito Bay, the electric boat above is the only non-paddling option.

The full price and tour-type comparison for all eighteen operators is on the register.

The thing that matters more than the boat

Whichever hull you pick, the moon decides what you see. A bright moon washes out the glow, and no amount of glass helps.

La Parguera has no full-moon closure, so Fondo de Cristal will happily sell you a ticket on the worst night of the month. Check the moon calendar and aim for the new moon. That single choice matters more than the difference between a glass bottom, a clear kayak, and an ordinary boat.

One more honest note about La Parguera specifically. It is the only bay where you can swim, it has the cheapest tours, and it is the closest bay to the south and west coasts. But it is not the brightest: Mosquito Bay holds the Guinness record for that, and if raw brightness is what you are travelling for, the glass is not what decides it. Our comparison of the three lays out that trade in full.