Possible Clues:

• Like a duck's feet
• Condition of duck's feet
• Like an otter's feet
• Some animals' toes connected by a thin fold of skin
• (Of feet) adapted for swimming
• Like duck's feet
• At the double, you started with your ducks' feet before the tide went out
• Nature of duck's feet
• Waves initially subsided a couple of feet so helping swimmer?
• Condition of a swan's feet