A boat sailing towards the pre-start side of the starting line or one of its extensions after her starting signal to start or to comply with rule 30.1 shall keep clear of a boat not doing so until she is completely on the pre-start side.
A boat taking a penalty shall keep clear of one that is not.
A boat moving astern, or sideways to windward, through the water by backing a sail shall keep clear of one that is not.
23. CAPSIZED, ANCHORED OR AGROUND; RESCUING
If possible, a boat shall avoid a boat that is capsized or has not regained control after capsizing, is anchored or aground, or is trying to help a person or vessel in danger. A boat is capsized when her masthead is in the water.
24. INTERFERING WITH ANOTHER BOAT
If reasonably possible, a boat not racing shall not interfere with a boat that is racing.
If reasonably possible, a boat shall not interfere with a boat that is taking a penalty, sailing on another leg or subject to rule 22.1. However, after the starting signal this rule does not apply when the boat is sailing her proper course.
Racing Rules of Sailing for 2013-2016; Version 6
Racing Rules of Sailing for 2017-2020
Great Britain - RYA has declined to grant a license for prescriptions and cases.
World Sailing Cases
World Sailing Q&As
Match Race Calls
Match Race Rapid Response Calls
Team Race Calls
Team Race Rapid Response Calls
World Sailing Judges Manual