The awful truth about Nova Cannons (with added edits)

Now that we've seen a shot fired in anger by a Nova Cannon, it's time to set a couple of things straight for their future use.
Because the designers never really intended them to be used seriously, the rules aren't up to the usual standard of clarity. So here's how I see it working in the future:

1. A Nova Cannon firing is pretty much the only thing you do during the turn; no use of the engines, weapons, or even shields. By implication I take that to mean that switching on the cloaking device is also off the agenda; you'll have to wait till next turn to do that.
2. The Nova projectile, annoyingly, sticks around for three rounds. During which time it moves. The first turn is easy enough; the projectile moves 6 inches straight ahead, detonates, and then cuts a swathe two inches wide and 18 inches long; anything even touched by that has a very bad hair day.
3. The conundrum which isn't really addressed by the rules is, what happens during the second and third rounds. The projectile moves in each round, with its zone of death getting bigger, but less dangerous, in each turn. The question is, does it move during the movement (in which case, when?) or during fire. John and I have decided, in the interests of sanity, that it moves during the fire phase. This is primarily to avoid the headache induced by potentially having to work out WHEN a ship might have moved through the path of the projectile if it moved during the movement phase (and thus work out whether it would have been in the path during the exact moment when the template was on that point). So after movement is completed, and before other firing takes place, the projectile does its thing.

Surprise news: I re-read the rules, and the above is actually what they say. I am Boris and I am INVEEEENCIBLE. I'd be even more invincible if I'd seen that the first time I looked at the rules.

Second edit; it ought to be clear to one and all that nothing in this post, or indeed in any other post, is intended to stomp on the Full Thrust rules where these already cover the situation and are clear. The campaign rules are intended to address the campaign structure and where necessary to clear up areas where we've discovered the rules don't quite cover something.

Talking it through over a beer with John, I concluded that a Nova Cannon would make a great weapon in a small ship which had nothing else, but is a complete bust with a large ship, because it really doesn't have the potential to do much damage to an adversary that still has the ability to manoeuvre and in order to use it, you have to switch off every other offensive and defensive system in the ship, which means that to use the Nova Cannon, you have to waste all the other points you put into the ship. From which it follows, why bother putting anything else on the ship in the first place?


It has been pointed out to me, amid much else, that the ship has to weigh at least 40 mass before you're allowed to put a Nova Cannon into it. Where's the fun in that?

The original rules said that a Nova Cannon could only go into a capital ship, and the threshold for a capital ship was 40. This doesn't seem to be changed anywhere else, though the ship design system has changed to the point where the Capital ship distinction no longer really exists the way it used to. And when Capital still meant something a Nova cannon weighed 16 and you could only have 50% of the weight of the ship dedicated to weapons. But this is all detail. And I'm sure it's all wrong anyhow.