I decided to take a stab at actually calculating the relative degree of fault of the two skippers (an exercise in futility if ever there was one).
First, given the speed of each vessel and therefore the amount of damage each could do: while neither speed is known exactly, conservatively we could say that the powerboat is moving five times faster than the sailboat (25 kts vs. 5 kts). Since the amount of kinetic energy varies with the square of velocity, a vessel moving 5X faster has 25X more kinetic energy than one of equal mass. So if the vessels are roughly equal in mass, the ratio is 25:1 or in terms of percentage, rounded to the nearest percent, 96 to 4. Thus, if both skippers are equally inattentive, then the blame ought to split at 96/4 according to how much damage they might do. If the powerboat is only going 4X the sailboat’s speed the ratio is 16:1 or 94/6. At 3X it is still 9:1 or 90/10.
But, were the skippers equally inattentive? Well, the powerboat skipper was objectively known to be not watching for some time since he rammed a large, clearly visible, nearly stationary (relatively speaking, of course!) object. The sailboat skipper may not have been paying any attention at all either, but that is not objectively known since he is a passive actor in the situation. Also the situation requires the sailboat skipper’s attention to be distributed around the entire horizon whereas the powerboat skipper need only be watching his heading to avoid the collision. Additionally the sailboat skipper need not be looking to hear the powerboat approaching, while the powerboat skipper must be specifically looking since he can’t hear a sailboat or warning shouts or whistles (likely) over the roar of his outboards. Thus the powerboat skipper’s failure to watch is more blameworthy than the sailboat by a factor of 4.
Then there’s the Colregs. The sailboat as stand-on vessel had no obligation to alter course until it was evident that not doing so would result in being hit. Arguably he even had an obligation to hold course up to that point. Now the point at which he must change course to avoid collision is highly subjective due to the high closing speed from a near head-on angle and the stress of the encounter, so failure to do so in time, while an error in judgment, cannot bear the same responsibility as the powerboat’s obligation under the regs to give way. So under the regulations alone, the powerboat skipper’s fault is something like 4 times the sailor’s.
And as has been mentioned there is the skipper’s responsibility to protect his passengers from harm. The sailor had one crew, the fishing captain had 6 crew and guests. Therefore the blame comes down 6 lives to 1 against the powerboat.
So overall by my calculation, we have 95 X 4 X 4 X 6 for the powerboat driver vs. 5 X 1 X 1 X 1 for the sailor. That’s a ratio of 1824:1, or in percentage terms, 99.95% power, 0.05% sailor – or rounded to the nearest percent, 100/0.
