Little over a year ago, if you went into your local software retailer and asked for a submarine simulator, all you would get was a vacant look. Now there is a fair choice, most of which are of a high quality, Sub Battle is no exception.

Sub Battle is set over the period covering the Second World War and allows you to play a number of different scenarios. Unless you choose to be an American then you start your command in 1939. When you take command of a submarine, you are assigned one of several different types depending again on whose side you wish to play. You can either choose the training mission, which involves sinking as many ships as possible then returning back to base in one piece. Then there's a single mission option which allows you to try out one of the sixty available missions at random. And finally there's the full war command, which takes you right from the start to the end of the war for your side.

Some of the missions may include patrolling a set area for ten days, destroying all the enemy shipping you can catch, then moving on to a different location and repeating the exercise. Or you might be asked to take urgent supplies to stranded troops in hostile countries.

The game design is very well executed. With a full map of the world showing your position, the enemy position and the location of your bases. The nearby area around you can be zoomed in on to give you a more accurate picture of what you're up against. Around the bottom and sides of the screen are the various gauges showing speed, heading, depth, view, ammunition and so forth. You also have sonar and radar at your disposal to help you plot a successful course to your enemy. These are essential pieces of equipment, because if you choose a high difficulty level enemy craft will not be shown on the map and the first warning you get of any enemy approaching will be a message from one of the crew flashed up on the screen, saying that they have a possible enemy contact.

A handy feature on the low levels is an auto navigation device, useful for getting from a to b. Just enter your destination coordinates, cruising speed, and you'll be transported there in a matter of seconds. Far easier than messing about trying to circumnavigate any land masses in your way. Another useful feature is the time compression key. Similar to a time acceleration key, you can have one second equal to five seconds, a half minute, ten minutes or four hours which is useful for long missions.

When you boat goes to battle stations, you have several ways of viewing the scene. You can stand on the watch tower and issue your orders from there while on the surface of the ocean, or you can use your binoculars. If you think the enemy looks too overbearing you can submerge and use the classic phrase 'up periscope'. The problem with being underwater though is you can only fire your torpedoes and not your deck or anti-aircraft guns. Each side has four different types of torpedo and are issued according to whether they had been discovered at the time you chose to play, as some torpedoes are not in use until 1943. Each style has different ranges, and a different chance of being dud. This is where the Americans were at a disadvantage, their Mk14 torpedo has a huge 62% chance of being dud.

The deck guns the subs are fitted with tend to have an average range of 12,000 feet, not much when you think guns aboard enemy ships can fire anywhere up to 54,000 feet! If a ship is getting too close for comfort and the deck guns are unloaded, and torpedoes are all spent, you can open up on it with the anti-aircraft guns, they don't inflict major damage but they fire fast enough to polish off a heavily damaged ship. As a last resort though, you could turn to ramming as an option. Or you could send out an SOS and abandon ship if the going gets really tough.

But never underestimate the enemy; if you're attacked by a convoy with an aircraft carrier, you are in big trouble. The first thing you notice will be black specks on the horizon, slowly coming clearer and clearer. Armed with bombs and depth charges, you are in trouble.

Though dead ships sometimes prove a problem, if a sinking ship is in front of your, any ship behind is safe from your fire because you automatically target on the nearest thing to head on.

One problem I did find though was that sometimes the controls were sluggish in their response to urgent commands like crash dive. Not that I'm complaining about the fact I was equipped with torpedoes not issued until four years after my mission.

Apart from these small gripes though, Sub Battle proved itself to be a very absorbing and comprehensive simulation with atmospheric sound effects and pretty good visuals.