Wayne.B wrote:

We have a ferry service running between here and Key West that uses
large, high speed catamarans. They can run at 40 kts or so and are
quite spectacular to watch at close range.

I had an encounter with such a vessel last summer cruising from Croatia
to Italy. I was 10nm from the Croatian coast on a NW course,
singlehanded under sail when I noticed the vessel astern on my port
quarter, at a guess circa 3 nm miles away - in the binoculars I could
see the twin hulls; I judged it to be in an overtaking position to me.

It was clearly traveling very fast and closing and the bearing did not
appear to be changing; it was a classic collision course situation - the
weather was clear and sunny, wind about 12knots, no other shipping
visible. The ferry, for that is what it was, stood on and was getting
very large, very quickly, and still coming straight for me, although I
was beginning to think I should already change course myself but because
of the speed of the other couldn't quite evaluate to which one.

By all interpretations of ColRegs I was the stand-on vessel but I was
beginning to get seriously frightened, I wasn't prepared to insist on my
rights, just wanted to survive, but I didn't know what would be the best
strategy - to stand on with no change of course by the other could
result in me being run down; to head up through to a NE course could
anticipate the other vessel's possible avoidance action but the greatest
confusion came because of the phenomenal speed of the other vessel and
my feeling of helplessness at trying to make any manoeuvre that would
get me away from such an object with my paltry 5-6 knots - I had started
the engine in case I needed the last ounce of speed. My VHF transmit
function had failed during my cruise so I couldn't call on channel 16.

In the event, I swung to starboard and round to a reciprocal and watched
incredulously as the ferry roared over my track during the next few
minutes without any change of speed or course, about where I would have
been if I hadn't changed course, I was then left tossing in the
maelstrom of a wake that was left. Very shaken.

It was a Croatian registered ship and there were figures on the bridge
as well as some passengers on deck to witness it all. With my white
sails in clear visibility at about 09:00 on a fine morning I must have
been seen.

So yes, it was "quite spectacular to watch at close range" but once is
enough, thanks.

BrianH.