For snorkeling, a secure wrist strap or short tether is usually the most practical choice. A tightened wrist strap can work well if it’s snug enough that the camera won’t slip off while swimming. Some people simply secure the existing wrist strap more firmly, which keeps the camera usable and close at hand.

A float strap is a good option if your top priority is not losing the camera at all, since it can keep it from sinking if dropped. Users report they work, though they can feel a bit bulky.

A short tether clipped to your person can also work well, especially if attached to something secure and kept short enough that the camera stays within easy reach.

For snorkeling specifically, the main tradeoff is that a float strap may pull the camera upward, which can be slightly annoying when you’re trying to aim at fish below or in front of you. So if ease of shooting matters most, a snug wrist strap or short tether is likely best; if recovery after dropping it matters most, choose a float strap.