Best underwater noisemaker?

[Dan]

I'll be the next proponent of using a metal pointer (lobster tickler) banged against the tank to signal a buddy. It works quite well for that purpose, plus as has already been mentioned then lets you point out something underwater and helps you stabilize yourself for pictures, etc.

I can hear the banging about 27’ away at least.
As mentioned previously in
December 24-31, 2017 Palau Trip Report
I expressed my desire to see a Zebra shark to Ripon, the lead dive guide on this dive. As we were cruising around 100 feet deep along a wall, Ripon turned to me and pointed to the bottom and gave a shark sign (an open hand on the forehead). I could see a shark-looking fish about 2 inches long on the bottom from our level. We descent to 120 feet deep to get a better look. It was just lying there sleeping. I pointed to him my camera and to the fish as a sign whether I could get down for a closer look. He raised his index and middle fingers (like a victory sign) and pointed to his dive computer. I interpreted it as I have 2 minutes to descend, take the dang picture and ascend to a safe level. I did as told and took the fish picture, below, at 147 feet (45m). I could hear my 2 minutes was up as he banged away his stick on his tank. That was the deepest depth I ever done in my 13 years of diving and may not do it again for sometime

 

[Zef]

With regards to "pointers", there is no reason to buy one unless you have a desire to have one. A dive knife, bolt snap, carabiner, or even the tail end of a dive torch are all adequate substitutes for tapping a pointer against the tank and one is likely to already be carrying one them.

-Z

 

[chillyinCanada]

Agreed, Zef.

 

[CT-Rich]

I am pretty deaf on the surface, more so underwater. I have never heard an alarm on my computer either. I guess that means I have no skin in this game, but, Sound travels too fast underwater to tell direction so it will not really do much to help locate your buddy. Rattles and bangers, to my mind do nothing but bring you closer to being a Christmas tree...

For surface signaling I have a nylon whistle, which I have never found the need to use. I do consider it an essential piece of safety gear since it does not rely on are air from my tank to work.