tread water (?.)

• abide
• bathe
• be still
• coast
• dive
• float
• freeze
• go in swimming
• go in wading
• keep quiet
• lie still
• mark time
• not breathe
• not stir
• remain
• remain motionless
• repose
• rest
• skinny-dip
• stand
• stand fast
• stand firm
• stand still
• stay
• stay put
• stick
• stick fast
• swim
• tarry
• wade