SeaArk has discovered the recipe for constructing the toughest boat on the market. Our 72" bottom Jons are built from .125 gauge aluminum. Our caprails are extruded and oversized to strengthen the top portion of the boat. Oversized ribs and rib doublers are used on the front four ribs, where the boat can take a lot of abuse. A 3/16" extruded keel is used to reinforce the center of the boat where the boat is most likely to be docked on rough surfaces. The 52" to 60" bottom boats are just as tough. They are constructed from .100 gauge aluminum and feature one piece extruded ribs.