Port visor?

[erice]

Rained last night, had to jump up to close all ports. Got stuffy quick. Got me thinking about port visors. Does anyone here use them? Pros, cons?

 

[mixman]

I'm not sure what other options are out there, but I saw these in an ad recently and have been considering further investigation:

http://www.atninc.com/atn-dorcap-sailing-deck-gear.shtml