200049 Overtaking and Hovercraft Manoeuvrability

Overtaking and Hovercraft Manoeuvrability
Report No. 200049

Let me give three overtaking scenarios, in all of which I was a participant:

1. North-east bound, approaching the Sandettie Bank in the 1970's. Own vessel making for the right-hand channel at 15 knots, with a course alteration to starboard in the offing, while on our starboard quarter was the a vessel doing well over 20 knots. She was tracking well clear of us until, at a mere 8 cables range, she decided to take the deep-draught channel, turned to port and scraped down our port side less than 2 cables off. I was far from impressed by the seamanship, but there was nothing wrong about the decision to overtake on the port side.
2. Almost the same location a few years later, this time with me doing 18 knots behind a flag-of-convenience bulk carrier. The Captain tried to pressure me into overtaking on her starboard side, but I wasn't having any. I overtook to port, reached the alteration position and turned to port to cross the lanes en-route for the English east coast - at the time I was less than half a mile ahead of the old bulk carrier.
3. Crossing the Dover Straits as Captain of a hovercraft, coming up on the starboard quarter of a ferry. He had a group of ships in the north-east lane on his starboard bow, so must be allowed room to alter course if needs be, but I am already tracking ahead of those same ships because of my superior speed. The only sensible option therefore is to nip down the port side of the ferry. This is a scenario that happens almost on a daily basis with hovercraft.

Lastly, one should always remember the old adage, that rules are "for the guidance of wise men and the obedience of fools". Every scenario should be considered on an individual basis, and a proper assessment of all factors that might come into play should be completed before making a firm decision. Whether or not it adheres strictly to the Rules, one must stick to one's decision and take the consequences.

While on the subject of collision avoidance, it is worth pointing out one other factor about hovercraft that most may be unaware of - they can be constrained by wind and/or wave direction when it comes to altering course. More times than I can count, from the days before illness brought on early retirement, I was crossing the lanes with a give-way vessel on a near-steady bearing when that vessel decided to alter course for us. Since our First Officer (as ever on the radar) had determined that a risk of collision existed, and since I didn't want to turn to starboard (into wind/wave), we had already opted for the large gap astern of that vessel and were tracking half-a-mile astern of him by radar. At 4 miles range we would, of course, still be on an almost steady bearing from him, so a decision to alter was quite understandable. However, the catch was that such vessels could rarely come round sufficiently to point at us before we were hurtling down their starboard side 5 cables off. This is not something that the people who draft the Rules bore in mind, which is one of the reasons why we always took independent action before any close-quarters situation developed. If we were doing all that in fog, when the inevitable bunching of ships that occurs means one has to zig-zag through gaps, then alterations could not always be made before the close-quarters situation was deemed to exist (i.e. when passing through a gap with the next row of ships only two miles off and the only gap meriting a smart turn to port). It all made for the most highly-skilled and superbly professional guys (and girls too, now) that I have been privileged to serve with!