Big Fin Bay

Big Fin Bay Slot Review

Slot Provider: Thunderkick

RTP: 96.14% | Variance: High | Maximum Win: 15,040x

Our Score: 7.4

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About Big Fin Bay

Reviewed by:

Published Date: 15th April 2021

How We Review Slot Games

We test and rate all slot games across 5 criteria, assigning a score out of 10 for each and an overall score that is an average of the 5. To build an accurate assessment of each game we gather information from the supplier and play in real play or demo mode. Find out more.

NOTE: Screenshots on this page were taken from playing Big Fin Bay for real money at Casumo Casino.

Big Fin Bay is a six-reel slot from Swedish game developer, Thunderkick. It has a fishing theme and retro style that look rather basic, but its high variance maths model is anything but. At the time of its release in February 2021 similarities were drawn between the games expanding reels format and the Megaways™ craze (that continues to this day).

Despite it’s 117,649 max paylines – the same as Megaways – Big Fin Bay isn’t a copy-cat slot, but rather one that finds its own place where reel expansions are reserved for the free spins round where the games best wins can be found.

You can take Big Fin Bay for a spin yourself at most UK slot sites at 10p per play.


Design and Artwork 

When you load up Big Fin Bay for the first time, you might, like us, be tempted to shut it right down again! But we recommend you give it a chance.

It’s an odd-looking game with a definite retro feel of back-to-basics graphical styles – you could almost be looking at something pinned on the wall of a seaside café in the 80s! The backdrop is a glistening Mediterranean seashore where fishing boats glide by, whilst front and centre sits your six-reel grid. On that grid are illustrated symbols that have an almost childlike quality to them and include a white bearded captain straight from a TV commercial.

Whether you enjoy this style will be a matter of taste but after a few spins we came to like it – there is something comforting about the simple graphics and sea shanty soundtrack.

Big Fin Bay Game Information

  • RTP: 96.14%
  • Variance: High
  • Maximum Win: 15,040x
  • Progressive Jackpot: No
  • Reels: 6
  • Rows: Up to 7
  • Paylines: Up to 117, 649
  • Minimum Stake: £0.10
  • Theme: Fishing
  • Features: Expanding Wild, Mystery Wilds, Free Spins

Big Fin Bay Review Scores

  • Gameplay and Features 7
  • Maximum Win 8
  • Theme and Design 7
  • Paytable 7
  • RTP and Variance 8

What Our Reviewer Says ...

"A fun, offbeat fishing slot with an alternative take on the expanding reels engine and bags of big win potential!"

Our Score: 7.4

Big Fin Bay Pros and Cons

What We Liked

  • Expanding wilds and re-spins
  • High top payout
  • Good high variance action
  • Free spins re-triggers
  • Slick design

What We Didn't like

  • Variance too high for some

RTP and Variance

Our Score 8

What is RTP?

RTP (Return to Player) refers to the amount a game will pay out in cash prizes expressed as a percentage of all the money wagered on that game. For example, a 96% RTP means a game will pay out £96 for every £100 wagered. This is an average number and will vary from one session to the next.  Read more here.

What is Variance?

Variance refers to how far a game will deviate from its RTP over time. High variance games deviate a lot and produce uneven win distributions and unexpected windfalls. Low variance games provide a more stable and even distribution of wins. Read more here.

The RTP of Big Fin Bay is 96.14%. That is average for Thunderkick games and most online slots. The variance is very high so don’t expect a regular distribution of wins. The game features are set up in such a way that the base game will be slow-paced but the free spins round can go off in a big way thanks to expanding reels and multiplier wilds.

Top Payout

The top win available in Big Fin Bay is 15,040x. That is good value though it is still under what you can find in the biggest paying Nolimit City or Big Time Gaming slots. You can also find higher potential in other games from Thunderkick like God of Rock (20,000x), Odin’s Gamble (19,333x).

Symbols and Paytable

Our Score 7

Big Fin Bay starts in the base game with 5,040 paylines in play across the six reels. To achieve this, each reel will have a different number of rows on it after each spin, but always the total number of visible symbols will be 27.

Wins are triggered by landing 3 or more identical symbols along a payline from left to right. Symbol values are Ok, but nothing special.

Low payers are the cards 9 through to Ace. Even the Ace only pays out 1.5x for six on a line, so you can see you aren’t getting much back there. Premiums are four colored fish and the sea captain. He is worth 7x for six on a line.

There are also Marlin Wilds subbing in for other symbols to complete win lines, and bonus scatters that will unlock the free spins round.

Features and Gameplay

Our Score 7

During the base game you will be looking for the Wild to land as frequently as possible. When it does, if it completes a win line then it expands to full reel height.  There is also a chance that a random Mystery Wild feature will be triggered, turning up to THREE reels completely wild.

That’s all good but what we are really counting on is the free spins round to drop. You need three or more bonus anchor scatters to trigger this. For each scatter you will get up to SIX free spins.

Across six reels that makes up to 36 free spins!

Now the Wilds have added value – each time they land they expand AND trigger a re-spin. When that re-spin happens, the wilds expand their reel by 1 more row to increase the paylines in play. These expanded reels persist in expanded format for the rest of the free spins.

And … if you can expand a reel to seven rows high, then you earn yourself 3 extra spins.

And for those who like the numbers (and Megaways™), six reels expanded to seven rows high is equal to the magic 117,649 paylines!

The Final Verdict

Our Score 7.4

Base game action is very slow in Big Fin Bay, and a few expanding wilds and mystery wilds isn’t really much to be excited about. But Thunderkick have built the bonus round in such a way that it can produce some very exciting cumulative payouts. How far you can go will depend on how many spins you got when you triggered the round. Most instances will be 5 to 10 is our guess, but with a possible 36 up for grabs, that is a lot of time in which to expand reels and build up multipliers as you work towards that 15,040x potential.

Overall, in Big Fin Bay, Thunderkick’s contribution to the expanding reels group of slots was a real grower. Initially the look didn’t work for us and we started to think this was a quick-release Megaways™ clone. But that is not Thunderkick’s style and they have in fact added a unique take to this thrilling  modern game format.

Who Made Big Fin Bay?

  • Name: Thunderkick
  • Established: 2012
  • UK License: 40165
  • Total Games: 55
  • Known For: Quirky, eccentric slots with fun features and distinctive designs
  • Popular Slots: Pink Elephants 1 and 2, Flame Busters, Birds on a Wire
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