No, I know. But based on testing, it doesn't seem to work that way at all. Even so, being under water while searching for loot just slows me down. And given that the way to loot is to move from area to area. I see way more loot spawn buy just swimming down the various canals. Going under water doesn't seem to yield more spawn points in any way. Perhaps the goggles need to be tweaked in some way?

I'd encourage you to test this for yourself, as I'm definitely not seeing increased loot spawn points whilst swimming under water.