Unfortunately salt water is hard for any machine to deal with. The F2 wont do well in the salt water. Because it doesn't have a manual ground balance it wont be able to deal with the minerals in the water very well.
The F2 is not a very good choice for a salt water beach. However, if you crank the sensitivity 'way down, set discrimination above foil, and sweep the searchcoil flat and slow, that'll probably tame it enough to be usable in the wet sand. In the actual water, probably not.
Excal 1000, Excal II, Sovereign GT, CZ-20, Tiger Shark, Tejon, GTI 1500, Surfmaster Pulse, CZ6a, DFX, AT PRO, Fisher 1235, Surf PI Pro, 1280-X, many more because I enjoy learning them. New Garrett Ca
A lot depends on the beaches too as not every beach is the same as to the concentrations of saltwater, amount of rain fall, or amount of black sand concentrations too. That is why true beach detectors cost so much more.