Scuba Dive

Durell Software published Scuba Dive in 1983. It started life on the Oric and was then converted to the ZX Spectrum, Commodore 64 and Amstrad CPC, with enough variation between versions that which one you load genuinely matters.

The setup is a single idea executed cleanly. A boat sits on the surface; below it is a stretch of sea with reefs, ledges and caverns. You swim down, take pearls from clams on the sea bed, push deeper into the caves for gems worth considerably more, and carry everything back up to the boat to bank the score. The largest payout is guarded by an octopus, which means going in among the tentacles and getting out again.

Two pressures work against you. The first is the wildlife: jellyfish, sharks and electric eels drift through the water, contact is fatal, and there is no health bar to absorb a mistake. The second is your air supply, which drains continuously and refills only at the boat. Since the boat keeps moving along the surface, surfacing is a small navigation puzzle of its own. Every dive therefore ends with the same decision - one more cave, or go up now - and that decision is the entire game.

Which version to play

The Commodore 64 conversion, the one that runs in the browser here, is not the strongest of the set. Its clams sit static rather than opening and closing, the scrolling is coarse and pixel-stepped, and the sea creatures behave more simply than they do elsewhere. The Spectrum release, with its rotate-and-thrust controls, conveys movement through water far better; the Oric original randomises the cavern layout, so memory helps you less. What all of them share is a tight risk-reward loop, an instant restart, and an unforgiving damage model. Half an hour is about the right dose before the repetition shows.