Not necessary on the battlestar Hobie 18. Theres enough glass on the bottom of the 18 from the factory. I can usually go 3 or 4 seasons hard before a glass job is required. Also, I've never noticed the hull strength compromised due to wear on a 18 or 16 for that matter. Wear on the bottom of a clam shell design is more difficult to repair properly and in my experience leads to hull failure. I like the F16 platform and would like the option of single handing. I solo the 18 currently but can't push it as I can't right it. Theres almost never anyone else on the water in N. Myrtle Beach.