Preliminary.
Risk of collision can, when circumstances permit, be ascertained by carefully watching the compass bearing of an approaching vessel. If the bearing does not appreciably change, such risk should be deemed to exist.
Sailing vessels.
Art. 17. When two sailing vessels are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other, as follows, namely:
(a) A vessel which is running free shall keep out of the way of a vessel which is closehauled.
(b) A vessel which is closehauled on the port tack shall keep out of the way of a vessel which is closehauled on the starboard tack.
(c) When both are running free, with the wind on different sides, the vessel which has the wind on the port side shall keep out of the way of the other.
(d) When both are running free, with the wind on the same side, the vessel which is to the windward shall keep out of the way of the vessel which is to the leeward.
(e) A vessel which has the wind aft shall keep out of the way of the other vessel.