Sea of Riches: an underwater take on the expanding symbol
Sea of Riches sends Play'n GO's familiar expanding-symbol bonus to the bottom of the ocean. The diving theme is calmer than the studio's tomb raids, but the maths underneath will feel familiar to anyone who has played a book-style slot. Here is the honest rundown before you play Sea of Riches.
The mechanics
Sea of Riches is a 5-reel, 10-payline slot themed around deep-sea diving and sunken treasure. A special symbol acts as both wild and scatter, and three or more trigger the free spins, where the slot's defining feature plays out. Before the bonus begins, one symbol is selected to expand. The underwater setting, with shipwrecks and marine life as the high-value symbols, gives the game a gentler mood than the high-octane explorer slots, but the structure is lean and purposeful. There is almost no learning curve, which is part of why this style of slot stays popular across so many casino lobbies.
RTP and volatility
Sea of Riches is a high-volatility slot. The base game is intentionally thin, and most of the return is concentrated in the free spins when the chosen symbol expands well. Play'n GO usually publishes a default RTP in the mid-96 percent range, but it licenses lower versions, so the figure can vary by casino. The graphics are identical regardless of the build, so the in-game info screen is the only reliable way to know what you are playing. Make checking it a routine, the discipline our RTP guide exists to build, and use our volatility guide to decide how much to stake per spin.
The bonus features
The free spins carry the game. At the start of the round, a symbol is chosen at random to be the expanding symbol. During the spins, if it lands enough to pay, it expands to fill its reel and pays across all positions, adjacent or not. Retriggers can extend the round and stack more spins on the same expanding symbol, which is when the big wins arrive. Draw a high-value symbol and a single bonus can carry the session; draw a low one and it usually pays little. That random draw is the entire risk profile, and it is why patience beats chasing in slots like this one.
How to play Sea of Riches
To play Sea of Riches you set a stake, spin, and wait for three scatters to land. There is no skill input, so bet sizing is the only lever in your control. Because the base game runs lean, a smaller bet that lasts through many spins gives you more chances at the bonus than a large bet that drains quickly. We always recommend trying the slot in demo or through a free spins offer first so the variance does not catch you out. Set a budget before you spin, treat any bonus win as a bonus, and stop when you reach your limit.
The verdict
Strengths: a calm, attractive theme on a proven format, easy to pick up, and the familiar tension of the expanding-symbol bonus. Weaknesses: high variance and the usual RTP-version fragmentation that you must verify yourself. Sea of Riches is an entertainment product, not a plan. Choose a licensed site from our reviews, learn the format in our slots guide, and for the studio behind it see our Play'n GO review. 18+, and if play stops being fun see our responsible gambling page.
Sea of Riches FAQ
Is Sea of Riches another book-style slot?
In spirit, yes. It uses an expanding symbol chosen before the free spins, the same idea behind the studio's book slots, wrapped in an underwater diving theme. The risk profile is that of a high-volatility slot.
Is Sea of Riches high volatility?
Yes. The base game is lean and most of the return sits in the free spins. Expect long dry runs and only stake what you can afford to lose. 18+.
Where can I play Sea of Riches?
You can play Sea of Riches at licensed casinos that carry Play'n GO titles. Use our reviews to choose a regulated site and confirm the RTP version on the info screen first.