Their is nothing you can do to prevent salt water and sunlight from slowly deteriorating your cables and connectors unless you coat them with a protector. Cleaning after each use with fresh water is a must and will prolong the corrosion more but no amount of cleaning will solve your problem when it's being submerged for hours day after day in salt water and sunlight. Look into a product that can coat your cables and connectors. Here's one I've heard things about. Doesn't harm plastic, rubber, vinyl or metal, it drys to a waxy water proof film and protects against salt water. Google it and check it out. It's a little pricey but I'm sure it's worth it.