I meant to show you how Duane rigged our vacuum sander, so I'll back up and do that now that we're finished!
I've said before, the bottom paint is nasty stuff. It's toxic (to keep the growth off the boat) and it sands off in a extremely fine dust. The boat yard requires that you contain the dust - nobody wants YOUR dust to land on THEIR boat!!
You can buy a rather expensive vacuum sander outfit, but we opted to use the items we already have.
Duane took some old Shop Vac hose that we had laying around in the hangar, maybe left over from a vacuum cleaner we had in the 1980's..... he took a piece of pvc pipe and ground a "slot" in it to fit on our little orbital sander. A little hard to see in the fuzzy photo, but he tightened a tie wrap around the pipe to keep in in place.
The fitting mates up with the tabs on the sander "output" port.
And to capture all the fine dust, we bought new filters and high efficiency shop vac collection bags.
And the setup worked amazingly well!
In the end, we sanded for 8 days - I'd say the sander was running 5-6 hours a day.
Countless 60 and 80 grit sanding discs
100 rubber gloves
6 vacuum cleaner bags
3 vacuum cleaner filters
3 - yes 3 - Black and Decker orbital sanders
2 Shop Vacuum cleaners