Yes. Rock lights are often used on the inside of the boat, but we would suggest using caution when using them on the outside of the boat. While they are designed to be waterproof, it’s worth noting that they’re not marine certified. This means that they shouldn’t be kept in the water for extended periods of time. If you are looking to add extra exterior lights to your boat, consider buying marine-certified lights that are specially designed to withstand saltwater, not leak, and not damage marine life.