How to find something in the water?

I need to find my sunglasses (very expensive) in about 20 ft of water. It’s a little dark until you dive down but there’s no way I can cover the general area and it also hurts my ears a bit. The bottom is mostly sand with a little seaweed. I was thinking a fishfinder but that only finds floating things… Can anyone give me some more ideas? Thanks

Powered by http://answers.yahoo.com

Is it possible to find lost disc golf disc that has been lost in the water with a fish finder or something?

Today i was playing a round of disc golf and I got distracted by some annoying and going-to-be-dead friends and accidentally threw my disc into the water. I went swimming in the lake for awhile to look for it but no luck. I was wondering if a fish finder could possibly help me find said disc (and maybe other peoples discs hehe) so next time i lose one in the water i could find it easily.

Powered by http://answers.yahoo.com