Crystal Waters slot review

The reels stand on the beach of a tropical island, with palms on either side, and the control bar is the standard one of the studio's "Real Series" (the line of games that it wires to a random jackpot). One pair of arrows sets the "line bet" from a floor of 0.01, a second how many of the twenty lines are live, while "Spin" needs no gloss.

In our screenshot "Fun Play" sits in both corners (which marks the demo), the dolphins stand "stacked" on the fourth reel, and the bet is 0.25 on each of the twenty lines, 5.00 a spin, with a win of 10 on line seventeen and the "random jackpot" counter at 2,569.26 in play credits.

The symbols are the dolphin, the yacht, the dwellers of the reef and the card values (nine to ace), drawn in coral and mother-of-pearl, and the sound is a splash at every win, which an hour of play teaches you to switch off.

The dolphin is the "wild" (it takes the place of any symbol but the yacht), and the studio put it on reels two and four alone, which means that it completes lines rather than starting them. Dolphins stacked on a whole reel (as in the screenshot) are the best picture that the base game offers. The yacht is the "scatter", paid wherever it lands.

Three or more yachts in view open fifteen "free spins", and during them a Bonus Fish swims onto the third reel, where it replaces the other symbols and carries a multiplier of two, four or eight on the win. With the dolphin on the same line the multiplier doubles again, up to sixteen (a figure seen once in a long season). It is the whole reason to sit at this machine.

The counter above the reels is the "random jackpot" of every Real Series title: a progressive pot, since each bet pours a few drops into it, which breaks on a spin of the machine's own choosing, at any stake and without a paying line. It then restarts from its "seed" (the sum it is reset to), and in the demo it climbs as it would for money, although it pays play credit.

Nobody at RealTime Gaming prints a theoretical return for Crystal Waters, so the "RTP" (what a slot pays back, as a share of all bets, over millions of spins) is not one number but a choice that each casino makes from the studio's settings, 96 per cent or thereabouts at the top. Where a house prints it, the number lives in the game's own help pages, which are worth a look before you put money on the reef.

More than the return, what shapes a session here is the volatility, which is very high: those 96 come back as a handful of large payments with long descents between them. Fifteen minutes of demo make the pressure felt. The balance sinks spin after spin and surfaces only when the yachts arrive, so that a player who dives with a small budget may not see the surface again.

Take a diver with sixty in credit: at 1.00 a spin (0.05 a line across the twenty lines) the tank holds sixty spins, and at the 5.00 a spin of our screenshot it holds twelve, barely time to get wet! The stake, far more than the luck, decides how long the dive lasts on a slot this volatile.

The reef is charted at the casinos built on RealTime Gaming, the Deckmedia houses among them (Decode, Ozwin and Fair Go as well as SlotoCash, Uptown Aces and Uptown Pokies), all six working the international market with a licence from Curaçao, the kind that the trade calls "offshore". How far such a licence protects a player, our SlotoCash review says, and the offers of those houses are on our lists for Australia and for the whole world.

None of those offers is fixed, and what applies is the casino's own page. The demo, which is the mode we used, is listed at most of these houses, after registration, as "practice" play, behind the "Fun Play" button that our screenshot shows. If you would rather not wet your own money, the "free chip" (a few dollars of bonus that no deposit precedes) is a second entrance, worth a close look.

Two lines of small print decide its worth, the "wagering" (how many times over the bonus must be staked before anything is paid) and the "max cashout" (the ceiling the casino puts on the payout), both explained on our free spins page. Here the first is a wall, since the bonus is more likely to sink before the free spins than to swim through forty times its amount; a chip is a snorkel, not a submarine.

Crystal Waters is a slot for the patient, and it asks what the deep asks of a diver: a slow descent, a budget that can sit through fifty empty spins and the knowledge that the surface, when it comes, comes all at once. For it speak the free spins with the multiplier of sixteen and the random jackpot; against it, the very high volatility, an unprinted return and a screen of 2011.

To a reader who loves the sea and has a diver's budget rather than a swimmer's we would name it among the sound choices of the Real Series, the demo being the first dive, as it was for us. Small and frequent wins live elsewhere, in the circus of Fruit Frenzy (2008) or at the stalls of Flea Market, and the rest of the games that we have described are on our slot and game reviews page (18+).