The swirl at the bottom of the tub, e.g.
Else clues• Eddy
• Maelstrom
• Spinning flow
• Spinning mass
• Tornado
• Whirling mass
• Whirling waters
• Whirlpool
• Whirlpool or tornado
• Whirlpool, e.g.
• Whirlpool, for one
• Whirlwind
• The shape of something rotating rapidly
• A powerful circular current of water (usually the resulting of conflicting tides)