While not strictly heraldry, I did find a recent Wooden Boat Magazine (based out of Maine) posting on Facebook pretty interesting.
It also reminds me of the use of lobster buoys here in Maine. Every lobster-fisherman has a buoy to mark each trap left behind which is identifiable by unique color and stripe patterns. I believe the patterns are even registered with the State. (Below are the buoys of my grandfather hanging from my deck railing, white with crossing green and orange stripes.)
I even devised arms which I attributed to my grandfather based on the buoy design. My grandfather did not live long enough to see these arms, and they aren't in use by my family. They exist mostly in my imagination, but I'm proud of the design nonetheless. Lobster-fisherman even post the same buoy on their boat, flying it as sort of a flag.