In Victorian Scotland there have been sightings of meteorites falling over Loch Ness. Alien life-forms have been spotted coming out of the Loch at night and terrorising the locals and could even be putting The Loch Ness Monster in danger. Something must be done to stop the creatures so you have come across an old Scottish engineer who has designed and built a diving-bell type craft before his death. The diving bell is powered by Water and Seaweed to produce a electric current to power the bell.
As the engineer was old and dying he asked you to pilot the craft and gave you brief instructions on how to use it before he died. You also have managed to get a surface ship to aid you by lowering you into the water, lifting you out and re-supplying you with spears and fuel. Before you dive you must indicate on a map of the Loch to the Captain where you need lowering to kill the alien life-forms.
Once in the murky depths of the dark water you view your surrounding world from a 1st person perspective. You have four windows in front, behind, port side and starboard side which can be looked out but beware as the craft will only go forward. Below the windows is your instrument panel with many instruments on it to keep you alive and complete your mission. Your main gauge to watch out for is your Oxygen and when it gets low (a bell will also warn you) you can use a pump to keep it topped up. A fuel gauge will also let you know your fuel levels.
You are able to move the craft by various devices and levers which enable you to move forward, turn left or right, and lower or raise the craft. A wheel used to turn yourself will also generate power for energy when used. To kill any alien life-forms you have a spear gun which has a limited supply of spears to use. You can fire the spears from any side of the craft as well as lower or raise the gun. If a life-form attaches itself to the craft you can also activate a electric field, they attach if you are stationary and will do damage to the craft. Your last defence is dropping bombs but if you don't operate the plunger when dropping the bombs and you don't get away from the area you will blow yourself up.
If you run out of spears or low on fuel you can sound a klaxon to get the Captain above to send you more down. Once the supplies have reached the bottom you can use your magnet to pick them up. You are able to switch your lights on and off to save energy and your last instrument is a compass. Once you have searched a certain area you can go back up to the ship and search another part of the Loch.