Hi Mark,
I'd check out the local T-shirt printers, and while you're at it, have them do a few shirts for the capt'n and crew too. They are surprisingly reasonable. The initial order will have a "setup" charge but even that may sometimes be waived if you can give them good quality artwork. Most will allow you to supply the shirts if you want. Most also will do embroidery as well. Look in the Yellow Pages under "T-shirts" or "Advertising Specialties".
Even a very small run of 5-10 items will cost no more than about $15/item (including shirt) for silk screening, less if you go the heat set transfer route. Embroidery works best where the image can be seen on one side only, like pillowcases or towels for the boat, hats.
Thanks again for letting me climb over your R-21 last summer... It really confirmed that the Ranger was the boat for me.
Alex G.