I had to make some washers for my fin screws tonight and thought I would make it easier to insert and remove them from the recessed holes on my boards with standard tuttle boxes. The holes are recessed about 25-30mm below deck level and are too small in diameter to get a finger either side of the screw head. By extending the rubber washer into a strip, two tabs are created allowing the screw to be placed perfectly. I dont know why I haven't done this before as most of the time when I need to get the screws out I have resorted to tipping the board upside down and shaking them out. You can sometimes guide the screw in and remove it on the tip of the screwdriver but this is hit and miss and magnetic tips don't work on 316 stainless. This should work well on thicker tailed boards with powerboxes also...
More info here...
whitelionwindsurfing.blogspot.com/2011/05/fin-screw-tabs.html