Possible Clues:

• Operatic boatmen?
• They get around in Venice
• Canal workers, for whom there's no hope, welcoming lido refurbishment
• Venice boatmen
• Who'd be hopeless types circling Lido ineptly?
• Craftsmen do in G & S role, possibly
• They stand up in the boat for the Odeon girls
• Gilbert's characters often engaged in long rows
• Grand Canal oarsmen
• Poles are put down by these Italians