Thanks, all.
Lesson to be learned, though: don't get tunnel vision! I remember one of the first lessons I learned in strafing attacks on flight simulators was that it's scarily easy to get so focused on the target that you forget about other things. Like the ground. Bad times.
I've just started a career - you know, just to see how long I last - and I looked up from some delicate setting of the AOB dial to find the destroyer I'd been eyeing up bearing down on me like the wrath of God, guns hammering away... My boat survived only by the skin of its teeth, with two snapshots on what was fortunately still a valid bearing and I left the tincan bubbling away in my wake. Still, it gave me a chance to try out the evaside turn-and-dive maneouvre...