Abstract: One or more embodiments of an elongated swim cap concavity (11a) having expandable walls (11) with flexible pleats (11b) above a draw cord sleeve (13) or (17) containing a draw cord (14) with knotted draw cord ends (15) and attached draw cord accessories (18) extending from draw cord sleeve openings (16) at the back and above an elastic ribbed perimeter band (12) with a plurality of grooved channels with ear notches (12a). These aspects provide a swim cap that accommodates various hair types, particularly thick, curly, long, kinky, coarse, voluminous and/or high-maintenance hair and/or chemically treated hair and/or braids, rolled locks or dreadlocks to establish and maintain a water-tight seal, a secure and stable fit, and a streamlined profile. Aesthetic possibilities are provided with visibility of and unobstructed access to the ears. Other embodiments are described and shown.