The "HD" model is designed to afford maximum hull support while keeping a low profile appearance. This design allows for easy access to your vessel because it is positioned inches away from your dock. Standard to the "HD" model is a fully adjustable "I" beam bunking system to gently cradle your boat. The worm gear driven winches are located on the dock* allowing for quick and easy maintenance. An elevated outside alkway allows access to both sides of your vessel for easy cleaning and maintenance.