- Sticking a foot in the water to slow the boat next to a mark. ILLEGAL
It's the same as if you would stick a paddle into the water: Rule 42 does not only prohibits gaining speed in that way, but also loosing speed.
- Pulling the main to accelerate down the leeward side of a wave. LEGAL
This is specifically allowed in rule 42.3(c), but only once for each wave or gust of wind and not on a beat to windward. The latter looks a little redundant because, how can you surf down the leeward side of a way going upwind. But there are also other waves on the racecourse. A wake of a passing boat for instance.
- Pushing down the centerboard in the mud in a shallow area just before the starting line to stay still in a current against the boat. LEGAL
This is the same as anchoring, which is allowed in RRS 45. You may also stand on the bottom and hold your boat.
- Repeatedly moving the tiller to turn the boat from head to wind to a close-hauled course. LEGAL
Another exception in 43.2 (d). Watch out though! Only when your moving slowly or are stationary. You may scull to a close hauled course but not PASSED that.
- Using the propeller (by turning on the engine) to get clear of another boat after a collision. ILLEGAL
You may use any equipment and the force applied by the crew of either boat but NOT the propulsion engine.
- Pulling in the anchor and let the momentum carry the boat over the starting line. ILLEGAL
Rule 45 states that you must recover the anchor before continuing racing but nothing about the momentum you have gained by pulling it up. You can find the answer in the Casebook. In Case 5 it is clearly stated: Recovering an anchor, whether it was lowered or thrown forward, so as to gather way over the ground breaks rule 42.1.
At an event with sponsored boats the OA asks the jury to write a Sailing Instruction rule which would disqualify any boat which is responsible for a contact. With or without damage. This is a condition of the sponsor for using his boats.
How would you formulate such a SI?