Gullsweep® - Bird Control for Boats Gullsweep® has been used around the world (for more than 40 years) to ward off flying critters that love to roost & mess on one's boat. The primary objective of Gullsweep® is to make gulls uncomfortable so they will select another roosting sight. Every bird has their predators and so they are always in a survival mode. Gullsweep® by its very unique nature creates the unknown fear that the moving object represents a potential danger. Thus with other alternative locations available, it is more suitable to go elsewhere. If a gull has been roosting, it is most important to clean up the residue promptly. Mess only creates more mess as it is a strong indication that the location is a safe one. Gullsweeps® are not expensive and can be easily mounted, dismounted and stored quickly when boating so that using several on a boat is very realistic and more effective.