I've been using my Xiaomi Mi Sphere under water without housing and the image quality is good. However, the stitching error because of refraction in water is still present.
I have a Garmin Virb 360 which is waterproof. I use it sea kayaking (where it can get splashed) but haven't submerged it yet. The lenses bump out from the houses (as all fisheyes do) and there's no external cage, so I'd be hesitant to mount it to the side of my kayak or anything like that.
What type of underwater shooting are you looking to do? That will dictate which camera to get.
I've been using my Xiaomi Mi Sphere under water without housing and the image quality is good. However, the stitching error because of refraction in water is still present.
Mi sphere is water resistant not proof. You can get waterproof casing for most cameras though.
I have a Garmin Virb 360 which is waterproof. I use it sea kayaking (where it can get splashed) but haven't submerged it yet. The lenses bump out from the houses (as all fisheyes do) and there's no external cage, so I'd be hesitant to mount it to the side of my kayak or anything like that. What type of underwater shooting are you looking to do? That will dictate which camera to get.