Where to get scuba gear in GTA 5? - There are two places where you can find aqualung.
How to equip a Rebreather in GTA Online
GUIDE] SCUBA Gear - Community Guides - GTA World Forums - GTA V Heavy Roleplay Server
The female model for the scuba suit has big male pecs and I find it kind of amusing. Also, no flippers (still not sure if that affects my swimming speed though) :
Infinite Cash Glitch Grand Theft Auto V Cheat | Attack of the Fanboy
How to Go Scuba Diving in GTA V: 4 Steps (with Pictures) - wikiHow
How to buy scuba gear in GTA Online
How to buy scuba gear in GTA Online
If only there were some way to glitch the scuba gear onto regular outfits : r/GTAoutfits
Solved - Hunt to keep the scuba gear (mask and/or tank) in freemode | Se7enSins Gaming Community
GTA 5 Online How To Put 'Scuba' Tank On Any Outfit After Patch 1.54 Cayo Perico Clothing Glitches - YouTube