You need to cross the Dover Strait TSS. Describe the correct method for crossing and what obligations apply to your vessel as a crossing vessel under Rule 10.

A. Rule 10(c) — Crossing a TSS: a vessel crossing a traffic lane shall do so on a heading as nearly as practicable at right angles to the general direction of traffic flow. The correct method for crossing the Dover Strait TSS: (1) Set a HEADING at 90° to the lane direction (the lanes in Dover Strait run approximately NE-SW, so a crossing heading of approximately 135° or 315° True); (2) Note: the RIGHT ANGLES rule applies to HEADING not to track made good — tidal set will move you along the lane, but your HEADING remains perpendicular; (3) Monitor other traffic in the lane using radar; (4) Under Rule 10(c), you are the give-way vessel in relation to vessels in the lane (who are proceeding along the lane direction); (5) Sound signal if appropriate; (6) Do not impede safe passage of vessels in the lane. The Dover Strait: most heavily trafficked seaway in the world — SW lane (vessels inbound English Channel heading NE), NE lane (vessels outbound). Separation zone between them.

B. Cross the TSS by aligning with the traffic flow briefly, then turning 90° once in the lane to cross to the other side. Joining the traffic flow first reduces the risk of collision with lane traffic.

C. Rule 10 gives crossing vessels priority over lane traffic. The 90° crossing rule means lane vessels must give way to crossing vessels approaching at right angles.

D. Right angles means your track over the ground must be perpendicular to the lane. Use a heading that compensates for the tidal set so your actual ground track is perpendicular, not your heading.

A. Rule 18 establishes the hierarchy for power-driven vessels underway. In order of priority (highest first — you must give way to all of these in this order): 1st — NUC (not under command): cannot manoeuvre, ultimate priority — Rule 18(a)(i); 2nd — RAM (restricted in ability to manoeuvre): limited manoeuvring ability — Rule 18(a)(ii); 3rd — CBD (constrained by draught): cannot deviate from channel — Rule 18(a)(iii) [note: CBD is optional display — not all CBD vessels show the signal]; 4th — FISHING (engaged in fishing with gear): Rule 18(a)(iv) — note this means fishing with nets/lines, NOT a vessel that has fishing equipment on board but is not actually fishing; 5th — SAILING VESSEL: Rule 18(a)(v) — power gives way to sail (with exceptions in Rule 18(b) where a sailing vessel overtaking a power-driven vessel must keep clear). You must keep out of the way of all five in this order.

B. Sailing vessels have the highest priority under Rule 18 as they cannot manoeuvre under power. All other vessels must give way to sailing vessels in all circumstances.

C. Rule 18 applies only when vessels are on a collision course. When vessels are not in a close-quarters situation, the hierarchy does not apply and normal right-of-way rules (Rules 12-17) govern.

D. CBD vessels have the highest priority because they physically cannot change course. NUC vessels can use their anchors or emergency steering, so they rank lower than CBD.

A. Rule 17 stand-on obligations: (a)(i) — maintain course and speed initially; (a)(ii) — when it becomes apparent the give-way vessel is NOT taking appropriate action, the stand-on vessel MAY take action to avoid collision by her manoeuvre alone; (b) — when a collision cannot be avoided by the give-way vessel alone, the stand-on vessel SHALL take action. The timing sequence: (1) Initially: maintain course and speed — Rule 17(a)(i); (2) Give-way not acting, situation developing: you MAY act to help (Rule 17(a)(ii)) — but only by altering to starboard (not to port for a vessel on your port side, as this creates confusion); (3) Imminent collision, no action possible by give-way alone: you MUST act — Rule 17(b). Sound signal Rule 34(d): if in doubt about another vessel's intentions, give at least 5 short blasts on the whistle immediately.

B. The stand-on vessel must maintain course and speed at all times until the give-way vessel passes. Taking any action while stand-on is a COLREGs violation that transfers fault to the stand-on vessel.

C. Rule 17 allows the stand-on vessel to take any action at any time, including altering to port, as long as it increases CPA.

D. The stand-on vessel must contact the give-way vessel on VHF and obtain agreement before taking any avoiding action under Rule 17.