I won't pretend to know everything about this boat cover.
The truth is that I was just walking by it one day on my way from the GSVVM to the hoist, and took the shot.
It looks like this may be a long-term cover for out of water storage, maybe even a winter cover.
The orange tarp material appears to be waterproof. It also seems to have been customized a bit to guarantee fit - not a bad idea considering the one-two-punch of wind and rain which do such a great job of keeping us on our toes during storm season.
I especially appreciate the bright orange color.
It's easy to keep track of and hard to miss.