Possible Clues:

• Ship rocks on wave
• Party exercise
• I emptied champagne cup, without right means to overcome shyness
• Moment to get acquainted with most of those in 4 down on the crest of a wave
• Start of many a party
• "Get to know you" activity
• Arctic path-clearing vessel
• Get-to-know-you event
• It gets people mixing cocktail ingredient right into tumbler
• Get-to-know-you game, and a description of this puzzle’s theme