That looks beautiful indeed! I think my wife shares some of the same hesitancy as you do lol I've swam in all kinds of places and yes it is a little scary sometimes not knowing how deep it can go but there's a lot to enjoy and appreciate with getting in the water!

Maybe bring a pair of swimming goggles with you? That way you can see the bottom and try to swim down to it to verify with your mind how far it is. A lot of times if it's 6 or 8 feet it's really not bad and very easy to go down to the bottom and jump off it if you need to get to the surface quickly!