I have several A3 sized laminated copies of the notice below which I will hang off my guard rails when in port to advertise my venture to passing by boaters - and perhaps get a few donations!
It's downloadable as a PDF should you feel compelled to print it off and stick it up on some notice board somewhere.
I have also 250 "business cards" so that I can give these out to all and sundry on my travels. They look like this: