BlackBook Bikini is a women-owned swimwear boutique on South Coast Highway 101 in Encinitas's Old Encinitas district, curating designer bikinis, one-pieces, and beach-to-street accessories at 960 South Coast Highway 101. The shop stocks labels including HYKAA, Vix, and Mara Hoffman alongside its own proprietary bikini line, a resort-wear mix that complements the handcrafted coastal jewelry at Gypsy Feather in the same neighborhood. Fit consultations address bust support, coverage preference, and torso-length sizing across triangle, bralette, underwire, and bandeau silhouettes for a range of body types. The boutique's accessories wall rotates seasonal cover-ups, hats, and statement jewelry, extending the beachwear corridor on Coast Highway 101 that includes Hansen Surfboards in Leucadia to the north. Core inventory features Italian-milled Lycra and Brazilian-cut bottoms with flatlock-seam construction, double-lined shelf-bra tops with adjustable hook closures, and chlorine-resistant fabrications rated for extended saltwater and pool exposure.