THEME: SUB is needed to make sense of 9 (nine!) maritime clues
GOOD ONES: Answers to starred clues {& theme} SUB
Lab growth below sea level? (SUB) CULTURE [not sure subculture is used by any but the troglodytic lest it offend those so grouped --- I still use it]
Underwater speaker? (SUB) WOOFER
Scenery for "Operation Petticoat"? (SUB) SET
BTW: Starting lineups A-TEAM [only if you're lucky --- needs "at times" given all the injuries]
Copycats APES [I get it, but I'm tired of this combo. Here we have an opportunity for a biological reference, which are too rare in Xwords]
RATING:

Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun