You really don't have to worry much about what's sharp or abrasive on the bottom. I anchored with rode once in PR, between Salinas and Fajarado, pulled the anchor up the next am and was hanging on half of the inner core that was left. Had we choosen to go ashore and wander the boat would have enjoyed a lovely time kissing the seawall. We were lucky then. Hope to stay that way.

Go Slow
Sail Far
Stay Long