Dive flags, whistles & signals in Puerto Rico

Fly a dive flag

What it looks like: red with a white diagonal stripe. It tells boats and jet skis that divers are in the water nearby.
Stay close to it. A flag only protects you if you’re near it. Plan your dive to stay around your flag, and come up next to it.
From shore: tow a float with the flag and keep your group together near it.
Snorkeling and freediving: fly one too. Boats can’t see a snorkeler’s head in the waves any better than a diver below.
On a boat: fly it high where it can be seen from every side.

A boat with divers in the water may also fly a rigid blue-and-white Alpha flag. It tells other boats that this boat can’t move out of the way.
Alpha marks the boat. The red-and-white flag marks where the divers are.
At night, a dive boat shows three lights one above the other: red, white, red.

When you see either flag, slow down and give it plenty of room. Divers can come up anywhere around a flag, and they’re hard to see.

Whistle: clip one to your BCD. Three blasts is the common call for help. It works when you’re tired and costs nothing to carry.
Dive alert or air horn: plugs into your low-pressure inflator and is much louder than a whistle. Useful on boat dives and in wind.
Underwater: a tank banger or shaker gets your buddy’s attention without surfacing.

Every diver should carry at least a whistle.

Surface marker buoy (SMB or DSMB): a tall inflatable tube. Send it up from your safety stop or inflate it at the surface so boats and your group can find you. Our DSMB course teaches how.
Signal mirror: small, cheap and visible from far away on a sunny day.
At night: a marker light on your tank or BCD and a backup light. See our dive light guide.

Puerto Rico has its own rules for dive flags and boating. Ask us, or check with DRNA (Departamento de Recursos Naturales y Ambientales).

We carry dive flags, floats, whistles and surface marker buoys, and we’ll help you set them up.