Underwater progressive slot machines use five reels and 18 paylines, and feature such extras as double-payout wilds, free spins, a progressive jackpot, and two bonuses stacked with multipliers. The machines accept coins from 0.02 to 5.00 and allow up to 5 bets on each payline. Bets may then range from 0.36 to 450 per game when all paylines are activated.
Underwater online gaming slots have non-scatter play read from left to right. Half of the symbols will award a payout, even with just two symbols on the reel. There are even two special symbols, the Jackpot Mermaid and the Star Wild, which will pay out even with just one of them on the reel. The jackpot is hit when the reels show five of the highest paying symbol, the Jackpot Mermaid.
The wild symbol casino player is the Starfish Wild and may be used to substitute for all other symbols except for the three pink fish. It also has added features, such as a double payout when it is used for a hit. If it lands on the leftmost reel, it becomes a paying symbol and is thus no longer wild. Wild symbol payouts depend on how many symbols come up in an active payline from left to right.
Underwater progressive slots also feature scatters which result in its own extras. The scatters, except for the Shark-Free Spin, have to show up on adjacent reels read from left to right.
1) Extra win scatter - This activates a mini-bonus of three shells, one of which the player must choose to uncover a multiplier.
2) Treasure Chest scatter - Having three or more of this in adjacent reels will trigger the Mermaid Bonus Game.
3) Porthole Bonus scatter - three or more of these will launch the Porthole Bonus.
4) Shark Free Spin scatter - when two or more of these show up anywhere on the reel, free spins are immediately awarded. The more sharks, the more free spins and a player may enjoy up to eight free spins at any time.
The Mermaid Bonus Game fantasy themed slots triggered by the Treasure Chest scatter features several treasure chests. A player must select his chest to get multipliers of up to 20x. His luck may also run out when he clicks a chest that says "Finish", thereby ending his game.
The Porthole Bonus casino games is a click-and-win game and is the same as the Mermaid bonus, with a player getting as much as 20x multiplier or finishing his game a bit too soon.