The instructions that come with this terrifyingly comprehensive submarine sim would probably be sufficient to wallpaper a small basement flat - even after being reduced onto microfilm, as they have been to fit them into the game's titchy cassette box. But fear not. With the aid of my trusty magnifying glass/potato peeler (it came free with 5 litres of multigrade) I've spent the last three weeks analysing them in every detail, and I can safely say there's nothing I don't know about underwater warfare.

A thorough explanation of the game's workings in the inadequate space I've been allotted would be impossible (and incredibly boring) so I won't even try it. Rest assured, however, that if it's got anything to do with submarines it's in there - from conning towers to Christmas trees. (No, really!) And if you're prepared to immerse yourself in it properly, Silent Service is an utterly absorbing game. All that's really missing is a proper submarine atmosphere, but that's easily provided by some pieces of red cellophane, a few holes strategically drilled in the central heating pipes and an obliging friend or relative under orders to shake your chair about at moments of tension.