And I realise… bother, @JGD, you can’t open that door as it’s a locked one. You need a crowbar. We can shoot it open, though.
If someone is spotted, enemy reinforcements will go towards him by the shortest route (splitting if they’re equal length). That’s actually good, because the dry-dock guys will be heading east. Scout, your sacrifice will be remembered.
A proposal: officer moves north, shoots door (auto success), saves an action. That leaves him still stealthy on the NW tile. Then sapper moves north and saves an action. We’re both still stealthy, so we can let the reinforcements head through the dry-docks towards the alarm point. Then next turn we can stealthy-shoot, move in and plant charges.
(correction to this, scout doesn’t have the +1 any more.)
Failing a visibility check was 1/3, missing each shot was 1/2, so that’s 4.2%.