I've seen retractable awnings on some newer sunseeker that appear to work like the residential models. Pretty impressive the coverage area for aft deck. Anyone know of these being put into boats after market?
I don't know what Sunseeker uses but the SureShade brand has become a popular factory option on many brands and is also available aftermarket. Although my personal experience with their system was limited to one afternoon on a new SureShade equipped boat, I was very impressed with functionality. I see they now offer a manual shade which seems like a great option for smaller boats or those not wanting to add yet another motor to the mix.
You may wish to contact AMG (Lars) for some insight. They are using the awnings on some of his Delta Powerboats (See images here http://www.sureshade.com/delta-powerboats/).