Drift Diving

How a drift dive works

On a drift dive, the boat drops divers upstream of the site and the current carries them along it. The divers don't fight the current; they relax and steer. The boat follows the bubbles or the group's surface marker and picks everyone up wherever they surface, so there's no need to swim back to an anchor line. Currents can be gentle or strong, and the best drift sites often have rich marine life, because currents bring food.

Many tropical destinations are known for drift diving, with reef walls and channels where tidal or ocean currents run reliably.

Before the dive

The briefing for a drift dive matters more than usual. It should cover the direction and strength of the current, the depth and profile, how to enter, what to do if you get separated and how the boat will pick you up. Agree hand signals with your buddy, and make sure your gear is streamlined with nothing dangling.

Entering and descending

In a strong current, divers often make a negative entry: they enter with no air in their BCD and descend at once, so the group reaches the reef together before the current spreads it out. This needs good weighting and quick, confident ear equalization. In gentler currents, divers may gather at the surface and descend together. If you can't descend, signal the boat rather than drifting away alone.

During the dive

• Stay close to your buddy and the group. In a current, a few metres can become a lot very quickly.
• Keep a little above the reef and avoid touching it.
• Use your fins to steer and to slow down, not to swim against the current.
• Watch your depth, because currents can include up and down movements.
• Some sites allow a reef hook, a hook on a line clipped to your BCD, which you place on dead rock to hold position while you watch. Use one only where it is allowed and never on living coral.

Surface marker buoys

A delayed surface marker buoy (DSMB) is an inflatable tube you send up on a line near the end of the dive, so the boat can see where you are before you surface. On drift dives many groups send one up during the safety stop. Practise deploying one in calm water first; the line must not tangle around you as it rises. Divers also carry a whistle and often a mirror or a light for the surface.

Risks

The main risks are separation from the group, being carried off a site, being hard for the boat to see and strong down-currents near walls. Dive with an experienced operator who knows the site, follow the briefing and end the dive together.

Frequently asked questions