Not my favorite port and we had a short day there but found a fun excursion with Seafaris. Went on their fast boat eco tour. It was fast and fun. Would do again since not much else to do in Grenada.
Walked up to Karel's bar on the beach and had Captain Mike take us over to Klein Bonaire to snorkel. Enjoyed the snorkeling and the beers back at Karels.
It was windy and overcast but still had a great time. Check out transportation over to Klein Bonaire ahead of time as the public shuttle is closed sometime.
But you don't really need to book this off the ship unless you have to.