A protective fender is provided for use on a pontoon boat having at least an upper support member and a lower support member. The fender includes an elongated body formed from protective material. A first fastening structure is connected to the body, engageable with the lower support member and moveable between a plurality of positions along a length of the body. A second fastening structure is connected to the body, engageable with the upper support member and adjustable to vary the position of the second fastening structure relative to the body.