In the rimfire world you might also look at the .17 Hornady Magnum Rimfire (HMR) It's new this year and basically a .22 mag necked down to take a 17 grain .177 bullet. Muzzle velocity is around 2600 fps. Ruger and Marlin chamber guns for it, and the Marlin won't set you back too much. Downside is that the extreme demand for this new chambering makes guns hard to find and Hornady is making ammo as fast a possible to try and keep up with orders.
The light bullet might be the best option when shooting around water to prevent or reduce dangerous ricochets. I would still exercise a lot of caution when shooting at water, as most recommend against it.
