Getting onto a boat for a week of chartering and finding out that you can’t charge your personal electronics is the worst. Avoid that situation by bringing your own 12V inverter, like the ProSport inverter from Professional Marine, which converts 12V battery power into 110V AC power so you can charge your phone, laptop, camera and anything else that might need some juice. The ProSport features an extruded aluminum case with power/status LED indicators, output short and input polarity protection, and a 250W surge capacity. The unit measures 6in by 25/8in, includes a 3ft power cable, and, as the name implies, fits in standard boat and car cup holders. $36.99,
