Then an orbital kinetic THOR/god-rod/Flying Crowbar is dropped on the offending vessel.
Not possible. Godrods cannot be made guided, and a moving ship will move out of the way by the time it descends.
I know.
I was just fantasizing/being funny...
Well, IMO, they CAN be made guided, MIRV's do it after all, but there's no way it could be cost effective. Margins are narrow enough.
Not to mention the intl. treaty problems for a commercial org to orbit space weapons are insurmountable.
OTOH, the solid state pizeo-electric actuators that are being explored for quasi-guided "smart shells" in the 30mm on down to .50 caliber might have some promise. I don't think fins would work, but maybe a "wiggling" drag stabilized conical tail might work.
There's not much time, but in the last few miles, some combination of GPS, and video/optical triangulation and passive recpeption of telemetry (on some freq. combination that can get through the ionized plasma sheath...) from the defending ship might be able to achieve "minute of trawler". Although "minute of zodiac" is too much to hope for. But it would obviate the need for any kind of optical sensor on the god-rod's nose, and would minimize the amount of onboard electronics, a tad...
Of course even a not-so-near miss could still be pretty bad... for everybody. What's the KE in joules of say... 50kg moving at 5000 M/s?
OK did some math... 6.25 x 10^8 J, assuming nearly 100% conversion efficiency on impact with the boat or the water. (Does not matter, really....) how's that stack up against a common torpedo or exocet missile warhead?