Be aware that power boat trailers have axles rearward,supporting the weight of the motors basically. A sailboat trailer will have axles near the middle of the trailer ,under the keel. Bunk trailers are prefererred to a roller one and bunks should be adjustable up and down to allow for different size boats to rest the wieght of the keel on the trailer. Side bunks are to stabilize only,not bear any weight in large amounts.