This enclosure affords alot of protection from the elements. The sides can be quickly rolled-up to adapt to changing weather situations. Also note the larger opening zipper window in the aft panel.  This vessel is owned by a US government agency.

This new bimini cover creates lots of shade for this aft deck. (March 2011-update, I just received a deposit for a new cover from this owner- he now has a much larger boat!!)