Picture this—you're anchored on the lee side of an idyllic island. The weather is forecast to remain stable, so you fall into your bunk without another thought. Overnight though, the wind shifts, and you awaken to the sound of waves breaking. You pop your head out of the hatch and realize that now the island is a lee shore and your anchor is slowly dragging toward it. Crummy way to wake up, huh?
While the free Boat Sentry app for iPhones and iPads won't do anything about unforecasted wind shifts, it can let you know if you're boat is dragging anchor. Boat Sentry is a fully customizable anchor alarm that will let you set safe zones that can be adjusted separately for each side of the boat to account for swing room. The app can run on multiple devices and even send out text or email alerts.