The International Regulations for Preventing Collisions at Sea 1972 (COLREGs) are quite clear:

Quote

Rule 8 (Action to avoid a collision)
(a) Any action taken to avoid collision shall be taken in accordance with the Rules of this Part and shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observance of good seamanship.

(b) Any alteration of course and/or speed to avoid collision shall, if the circumstances of the case admit, be large enough to be readily apparent to another vessel observing visually or by radar; a succession of small alterations of course and/or speed should be avoided.


(text in Bold highlighted by me)

a 10 degree change when approaching head on is easier to see than a 20 degree course change when approaching at an oblique angle.

Since neither vessel was constrained by draft (chuckle - they are catamarans...) then ultimately both captains are at fault, although one boat will be most likely be significantly more responsible than the other, which didn't apply Rule 8 in a timely manner.

Last edited by Zanshin; 07/02/2019 10:47 AM. Reason: changed "skipper" to "captain"
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