Possible Clues:

• Marine feature that could be permanent
• Move hand to and fro as greeting
• One might be caught near a beach
• Move to and fro
• What a slendid idea to have a bra in this!
• Put hand up as gesture we hear to surrender
• Roller; a gesture
• Marine feature which may be permanent
• Surfer's delight
• Breaker, e.g.