• IKEA mattress protector
It sounds silly, but this mattress protector is awesome and it's totally saved my mattress. Basically, it's a thin, terry-cloth cover that's backed by a waterproof membrane, and it works really, really well. It earned its keep when we were out for a nice daysail around Conanicut Island here in R.I., and upon re-entereing Narragansett Bay's East Passage (where the water can get really choppy), we took a decent sized wave over the bow, and being a nice calm day, the forward hatch wasn't dogged down. My mistake. The water poured in and soaked all our bedding, but thanks to this mattress protector, our awesome latex mattress (if you're gonna live on your boat, you need a comfy mattress) was bone dry. Thank God, because I have no idea how I would have rinsed and dried it, and it probably would then have always felt dank. The best part is that this protector is less that $30 for the king size, which fits my v-berth almost perfectly.