I replaced those little lights a couple times. They have 4 individual LEDs on the ones I have and i think they were getting hit w/ rocks and stuff off the road or leaving a gravel ramp, not necessarily getting into the water. I just replaced them with Rigid Lighting marker lights. like literally just wired them a couple days ago. They cost a ton more than the ones that came on your trailer but they look bulletproof and and substantially brighter even in their mid-level brightness (I think rigid offers 2 levels of brightness/power).