Underwater communication when scuba diving

Recently, I went diving off the coast of Kagoshima, Japan. We were two divers, my dive buddy being the 53 year old guide of the local dive shop. Conditions were good and we went quite deep to have a look at a soft coral measuring more than 3 meters in diameter.

When I started to feel the effects of nitrogen narcosis I hit my metal stick against my tank creating a hammering noise to attract the attention of my buddy. The striking of the metal stick against my metal tank was clearly audible to me. Still I didn´t manage to catch the attention of my partner. Apparently, he could not hear the noise. The most probable reason to this is hearing loss due to age.

I felt more and more uncomfortable and the urgent need to ascent to a shallower depth. Finally, I managed to make visual contact and to communicate my needs.

When diving, it is a good idea to once test the means of acoustic communication.

This is especially the case when diving with an unfamiliar dive buddy of middle or higher age.

Personally, from now on, I will always test acoustic communication by performing a "sound check".