For something temporary on a few particular trips, I rigged up a base for an inexpensive umbrella. I didn't want anything permanently mounted on the boat. The base is inexpensive PVC pipe. One vertical pipe is a diameter that will accept the umbrella shaft. The seat pedestal will fit though the other vertical pipe. They are connected by four T fittings. I put this on the rear deck with the chair holding it in place. The base can be rotated around the seat to get better shade depending on the sun angle. We get quite a bit of shade from it, and the umbrella can be easily be removed and tied down to run on pad.
Edited by Flippin-Out (02/20/16 09:15 AM)