A few documents that might be of interest.
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US Code: Duty to provide assistance at sea

(a) A master or individual in charge of a vessel shall render assistance to any individual found at sea in danger of being lost, so far as the master or individual in charge can do so without serious danger to the master’s or individual’s vessel or individuals on board.

(b) A master or individual violating this section shall be fined not more than $1,000, imprisoned for not more than 2 years, or both.

Explanatory note: Section 2304 requires a master or individual in charge of a vessel to render assistance to those in danger at sea if able to do so without seriously endangering the vessel or crew.

Definition of "vessel": The word “vessel” includes every description of watercraft or other artificial contrivance used, or capable of being used, as a means of transportation on water.

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Racing Rule 1.1: Helping Those in Danger

A boat or competitor shall give all possible help to any person or vessel in danger.

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ISAF Case Book - CASE 20

Rule 1.1, Safety: Helping Those in Danger
Rule 62.1(c), Redress
When it is possible that a boat is in danger, another boat that gives help is entitled to redress, even if her help was not asked for or if it is later found that there was no danger.

Summary of the Facts: Dinghy A capsized during a race and seeing this dinghy B sailed over to her and offered help. A accepted help and B came alongside taking the crew of two aboard. Then all hands worked for several minutes to right A, whose mast was stuck in the mud. Upon reaching shore, B requested redress under rule 62.1(c).

The protest committee considered several factors in its decision. First, A’s helmsman was a highly experienced sailor. Secondly, the wind was light, and the tide was rising and would shortly have lifted the mast free. Thirdly, she did not ask for help; it was offered. Therefore, since neither boat nor crew was in danger, redress was refused. B appealed, stating that rule 1.1 does not place any onus on a boat giving help to decide, or to defend, a decision that danger was involved.

Decision: Appeal upheld. A boat in a position to help another that may be in danger is bound to do so. It is not relevant that a protest committee later decides that there was, in fact, no danger or that help was not requested.

and one for fun:
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Case 67

Summary of the Facts: Under the government right-of-way rules applicable, W, a boat that was racing, was required to keep clear of a sailing vessel to leeward, L, that was not racing. W wished to sail a lower course to a mark and hailed L, which refused to respond. W then intentionally hit L by bumping her boom several times, thereby causing damage.

L informed the race committee of W's behaviour. A hearing was called, and W was disqualified for breaking rules 11 and 14. W appealed on the grounds that the racing rules did not apply, and consequently the protest committee was not entitled to disqualify her.

Decision: Appeal dismissed. The preamble to Part 2 of the racing rules makes it clear that, when W met L, they were bound by the government right-of-way rules. However, W was also subject to the racing rules other than those of Part 2. W did not observe the government rules and, by intentionally hitting and damaging L, committed a gross breach of not only a rule but of good manners as well.

The decision of the protest committee is upheld, but W is disqualified under the government rule applicable and not under racing rule 11 or rule 14, a rule of Part 2 which would have applied only if both boats had been intending to race, or were racing or had been racing. W also committed a gross breach of the government rule and a gross breach of good manners, and was therefore subject to further penalization under rule 69 (GROSS MISCONDUCT).