You get sea grass on AC because of the reef from what I understand. Some places rake it up to make the beach area more pleasant. But from a pier swimming is just fine, can even do some snorkeling, some have sunken pots to attract fishes. During April/May there can be Pica Pica, not sea lice, but teeny tiny oganisms that can get in your suit and cause a rash. Have only seen one post about someone getting it so far this year, but we bring Safe Sea lotion just in case. Do a search on Pica Pica if you want to find out more.