The term "vessel not under command" means a vessel which through some exceptional circumstance is unable to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel.

The term "vessel engaged in fishing" means any vessel fishing with nets, lines, trawls, or other fishing apparatus which restrict maneuverability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict maneuverability.

Two vessels: left - "I intend to overtake you on your starboard side"; right - "Yes ( _ . _ . )" or indicate such doubt by giving at least five short and rapid blasts on the whistle or flashes.