Fear of water is a terrible thing but, after playing this game, I'm afraid to even go out in the rain.

Patrolling a length of coastline, you have to clear it of marauding sharks which descend the screen in Centipede fashion. You are armed with a harpoon gun which only fires upwards, although your ship can move in all directions.

You start on the south-east coast with land in the top left-hand corner of the screen. Guarding the orange earth is a crab who can kill you, but cannot be shot.

You also face mines which on the first screen scroll up from below you, but change direction in later stages. Electric eels scan the edges of the display' and, as in Grid runner, can electrify a horizontal or vertical line of water.

Faced with this marine mania, you have to harpoon all the sharks to move on to a new section of infested water.

If you fail to spear the sharks before they reach the bottom of the picture they turn into little men called Nernoids.

These zip around the sea like a ball in Breakout and where two collide, spawn a horrid, grinning baby Nernoid.

On clearing a zone you move in a clockwise direction round the land, with increasing numbers of sharks and mines on each coast. On the west, a current also drifts you to the south.

The display is interesting at first but the large number of small, moving characters make following all the action very difficult on later coastlines.

Good ideas here but the screen gets too hectic and it will be a very mercurial mariner who sees the whole of this coastline.