SeaStatus
Surfing, sailing, swimming, skiing, snorkeling — no matter what you're doing on the water, you're going to want to check the conditions before you head out. SeaStatus has you covered. This free iPhone app offers you a bevy of information for over 2,000 different seaside locations in the U.S., including things like wind speed and directions, temperature, weather conditions, swell height and direction, water temperature, high/low tide, and even 48-hour forecasts.