Start talking ahead of time to each other. While no hail is required you can still give him the "courtesy" of pointing out you are on starboard.

finish your hail by beginning to count loud enough for him to hear you, "one one thousand, two one thousand, three one thousand...." Record or remember what count you got to when you took avoiding action.

Then protest him and say you were at x one thousand when you took action because he did not take appropriate action.

Or you may count to 5 one thousand and repeat your hail and count again. Anything to get his attention and make him realize he's not responding.

Give the protest committee the detail of your hail(s) and counts in your protest. It will secure the timeframe.