Most handheld GPS have some level of water resistance. In the case of my Garmin Montana 650, it is rated by Garmin as IXP7Did you have to protect the gps from getting wet?
That's the problem of living near the water, it's not so much the good weather, it's when the weather turns. Since there isn't anything that can break the wind or the waves they can really come close to your house and the experience can be frightening.