Leaving Peanut Island via Swimming

My friends are I are planning a full-day trip to peanut island this weekend. The ferry service only runs from 10am-5pm everyday. We would like to stay on the island until later, especially since sunset isn’t until 8pm now. It appears on Google Maps that the closest part of the mainland is a boat dock less than 200 feet away from the west side of the island.

Does anybody know if that body of water is safe to swim through?

We won’t be carrying much stuff with us so we don’t have to worry about the swim.