Tweet, tweet, flash, flash – How Do You Communicate While Diving?


We all learned in our beginning certification course how to use some basic hand signals to communicate underwater. As we mentioned in a previous post about full face masks that have integrated electronic communication, many of us still rely on hand and other underwater signaling methods.

Fortunately, many of hand signals are fairly universal, such as the thumb & forefinger OK sign, the horizontal palm down across our chest to signal out of air (hopefully one you’ve never had to use) and pointing your thumb up or down to signal ascent or descent.

Divers use hand signals to identify marine life too!

Did you know there is a whole set of hand signals to communicate what kind of marine life you’re seeing? For example, gently flapping your arms means a manta ray, your hand on top of your head with your fingers pointing up means a shark and a wiggling your fingers with your hand held down means an octopus! For more hand signals, check out this graphic.

Writing Instruments:

Of course, an easy way to communicate exactly what you mean is to carry a slate specifically designed for underwater use. You can clip one onto your BC, like this Cetacea Slate or attach one to your wrist like this one.

Do you know how to communicate on a night dive where there is almost no visibility?

You should work out your signals ahead of time if you and your buddy haven’t done a lot of night diving together. You’ll need dive lights you can easily maneuver underwater (make sure you have a backup light – the last thing you want is your only light to fail underwater at night). You should also have a light attached to your tank.

A flashing strobe that can be seen far away underwater and on the surface is also a good idea to have on you for both night and day diving.

Light Hand Signals:

You can shine your dive light onto your hands and use traditional hand signals, but this only works if your dive buddy is pretty close by. Basic movements include moving your light in a big circle to signal you are OK (but not pointed at the other diver’s eyes!) and waving your light rapidly back and forth means something is wrong.

What about Sound and Other Ways of Communicating?

Being able to make a recognizable sound underwater is not only convenient, it can be a lifesaver in an emergency. Of course, you can always bang on your tank, but that sound doesn’t usually carry very far.

Sound Signaling:

  • A better bet is to carry a whistle that works underwater, like this Storm Whistle. This whistle can be heard from up to 50 feet away.
  • Another affordable option is an underwater shaker like the Aqua Maraca, which can be heard from about 30 feet away.

What about Signaling the Boat?

Surface communication kit

DAN Surface Signal Tube Kit

Whistles and shakers might not be enough on the surface if you need to signal a boat, which isn’t uncommon in drift diving. Signaling the boat can become critical in an emergency if you have to make an ascent far from the boat too.

You can signal the boat using sound and visible accessories such as lights, and inflatable buoys and surface tubes.

  • Some options for sound signaling include air horns like this Dive Alert 3, which attaches to your BC inflator hose.
  • Brightly colored inflatable tubes like this DAN Surface Signal Tube Kit are simple to use (and are required in some parts of the world). They roll up and fit into your BC pocket, and once inflated, they stand up so they are easy to spot. This kit includes a whistle and signaling mirror (right).
  • If you’ve got a little spare cash, you can carry this Nautilus Lifeline GPS radio, which enables you to use VHF marine frequencies to talk with the boat or send a distress call on the universal Ch16. It can send your GPS coordinates to any marine vessel’s radio within 8 miles.

We have a whole line of dive lights and signaling devices at Scuba Toys! Shop online or stop by the shop in Carrollton, Texas.

What kind of signaling signals and devices do you use while diving? Have you ever had to use one in an emergency? Let us know in the comments section below!

Image attribution:

Article Name
Tweet, tweet, flash, flash - How Do You Communicate While Diving?
Divers communicate via hand signals, which are taught in basic certification classes. Noisemakers, lights and surface signaling devices make underwater communication better and safer.

6 responses to “Tweet, tweet, flash, flash – How Do You Communicate While Diving?”

  1. Sheryl V. says:

    Back when I was young, carefree and careless, I was night diving with my boyfriend in Grand Cayman. We each had a big dive light, but no backups. My light suddenly quit working and it was freaky dark. Fortunately, I was able to bang on my tank so my boyfriend was able to find me and of course, being young and stupid, we continued our dive and I just stuck close.

    Now in my older, wiser years, I carry a regular light, a backup, a tank light and I have a storm whistle like the one you mention.

  2. DJ Halloran says:

    I was on a drift dive in Cozumel and when my buddy and I surfaced, it was raining and we were pretty far from the boat. Fortunately, he had an air horn, so the boat was able to find us. Now I carry one too.

  3. Paula W. says:

    A surface marker buoy is required for all of the liveaboard dive trips we’ve been on, so I carry one even on day trips now.

  4. Jose Paas says:

    My crew and I typically just use hand signals

  5. Vic says:

    I’ve been interested in the slates. I’ve heard they are good, but haven’t actually used them myself.

  6. M. Rollins says:

    Hand signals work just fine in my opinion. I know some guys that use more advanced methods of communication, but I don’t feel the need at this point in time.

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