1) Avoid a suit 2) Barely enjoy the pool 3) Barely swim 4) Bathe in the buff 5) Be unsuited 6) Drop the suit 7) Environmental fiction book 8) Eschew the swim suit 9) Forgo the suit 10) Go in without a suit 11) Served with 29D 12) Skip the swim suit 13) Swim for a dark night 14) Swim in the buff 15) Swim in the nude Found on https://www.crosswordclues.com/clue/skinny-dip