I saw a picture of a pelican flat stern with what appeared to be foam flotation strips applied to the side at the water line for improved stability. Has anyone tried this? How does it work? Where do you get the foam?

chine runners or something
those are called chine runners, i think. the strips are there to give a little extra stability, to keep water out and maybe to buffer against docks, etc.

chine runners
where do you get them?

Sportspal also does that