the bikini is the official uniform of beach volleyball...i think you can be penalized for wearing too much clothing..
BEACH VOLLEYBALL TEAMS' UNIFORMS GUIDELINES FOR GAMES OF THE XXXII OLYMPIAD TOKYO 2020
www.fivb.com
6. WOMEN’S UNIFORMS
Style (see Appendix-2 : Women Athlete’s Uniforms)The TOP (as per Option 1) must fit closely to the body and the design must be with deep cutaway arm holes on the back, upper chest and stomach(2-piece), respecting the space required for the manufacturer logo, athlete number, national/territory flag, 3-letter country code, and the place for the athlete’s name.
The BRIEFS (as per Option 1) should be in accordance with the enclosed diagram, be a close fit and be cut on an upward angle towards the top of the leg.
The ONE PIECE (as per Option 2) uniform must closely fit and the design must be with open back and upper chest, respecting the space for the required inscriptions to be made.