No none at all. I did use white and I scrub it with a hard brush often. You would think it would hold onto dirt but not in my case. The boat lives in Mexico so maybe it just Mexican dirt that doesn't stick...My original non skid was like an ice skating rink when wet. In ten days my none skid...
Steven, yes as gattyh said I was in the middle of a refit and the aft lowers just weren't installed at the time of that photo. garryh yes Kiwi grip. I loved that part of the job. Went so fast and easy and is holding up great. I recommend it without hesitation.
Above is an in process photo of the install. I will post a shot of the hatch over the head process below. I do have aft lowers but they aren't installed in that picture as I was doing a major refit and had just put the rig back up.
I did not cut away anything but I did build up with wood around the old frame to make the Lewmars fit. I glassed over the wood. I sure hope my boat is a MKII or I've been wrong for 30 years. She is a 1971 hull #184
While these Lewmar Ocean Series hatches don't address the bulky issue they are serious off shore hatches. It would require cutting out a lot of fiberglass structure to get hatches low to the deck on these boats and I wasn't willing to give up the structure - strength.