General advice for phones etc. dropped into water.
1. Remove the battery ASAP. This is vital.
2. If it's fallen into anything other than fresh water, wash it in fresh water. This is particularly important if it's sea water. Salt will cause corrosion. You may just get away with it from fresh water if you ast quickly.
3. Dry it as well as you can with a towel.
4. Put it in a tupperware container or similar with some fresh silica gel. (Much better than rice, but rice is better than nothing) Once every day or so, remove the silica gel, warm it up in a low oven to dry it out, return it to the sealed container and phone.
5. After a few days, put the battery back and try it out. If nothing, remove the battery and continue drying.
No guarantees, but I've had good results in the few times I've done this.