Terror of the Deep

From game instructions
THE GAME
It is the close of the nineteenth century. A number of large, meteorite-like objects have been seen falling from the skies over Loch Ness. Strange creatures are reported to be rising from the Loch at night, threatening the lives of the locals, and even the legendary Nessie herself.
By the side of the Loch lives an ancient and extremely eccentric Scottish engineer, who has developed an extraordinary bell-like diving craft to explore the mysterious depths of the Loch. The engineer is now dying, and selects you as the one to complete his mission, using his craft to clear the Loch of its alien population and save his favourite monster. Unfortunately, before you can receive full instruction in operating his craft, the engineer's eyes close for the last time ...
Your strange craft is now being lowered into the icy waters of Loch Ness and you are poring over a map to decide where to dive first. The local newspaper is standing by to report your progress.