The Bob Marlin Goes Deep slot takes you aboard a charming underwater fishing expedition, led by Bob Marlin himself, a cheerful angler logging netted catches adorned with cartoon charisma.

The aquatic theme features sunny seascapes, vibrant reefs, and playful animations, blending relaxation with progression-driven gameplay. Instead of simple spin wins, the slot evolves as you collect fish and expand the reel grid, offering a strategic goal beyond random outcomes.

Beginning the game is seamless, though a few settings help tune your experience.

• Preferred Spin Options: Opt for manual spins when you want direct control or select Autoplay to sit back and watch Bob at work.

• Bet Options: Wagers range from 0.10 up to 125.00 coins per spin, appealing to both cautious players and those staking larger amounts.

• Turbo Mode: Engage Turbo Mode to reduce animation delays, especially helpful if you prefer faster spin cycles and less downtime.

Your goal is to land matching symbols on adjacent reels starting from the left across an initial 5 x 4 grid with 1,024 ways to win. Wins typically require three matching symbols, unless you hit super-high-paying fish symbols that pay for just two.

As you progress during your gaming session, special Bonus symbols expand reels, one row per Bonus up to a maximum of three, growing the grid to a 5 x 7 layout and unlocking up to 16,807 ways to win. On the reels, the symbols that appear include: 

• Card royals (J, Q, K, A). 
• Worm cans. 
• Lures.
• Tackle boxes.

• Expanding Reels: Bonus symbols land only in the base game (on reels 1, 3, and 5) and each adds one lower row when they appear. Up to three can land on a spin, unlocking the full 5×7 grid, altering the standard 1,024 ways into up to 16,807 ways to win. These expanded rows are essential for collecting special fish.

• Collectable Fish: When reels are expanded, Collectable Fish symbols, orange, blue, green, or purple, appear only on the added rows. Each colour has its own meter; collecting 5 of the same colour awards 5 Collection Free Spins. New players start with 3 orange fish pre-filled. Colours complete in the order Blue → Green → Purple → Orange when multiple are complete at once.

• Collection Free Spins: Triggered by completing a fish collection, this mode grants 5 free spins on the fully expanded 5×7 grid. The game replaces standard symbols with Super High-Paying fish of the completed colour. Collection Free Spins use your average bet size used during collection spins. This mode boosts reward potential, though no Collectable Fish or Scatter symbols appear here.

• Standard Free Spins: Landing 3 Bonus symbols in a base-game spin awards 10 Free Spins on the expanded grid. During this feature, Collectable Fish and Bonus symbols do not appear, so progress toward collection isn’t possible. It provides increased win opportunities via more paylines but without progression mechanics.

The Bob Marlin Goes Deep slot does not offer any Bonus Buy or Ante Bet options. 

I found the Bob Marlin Goes Deep slot to be a relaxing, goal-oriented slot that caters well to players who enjoy steady, collection-based progression rather than high-octane volatility. While the theme feels familiar among fishing-styled slots, the expanding reels and fish-meter collection mechanics introduce a satisfying long-term engagement loop. With an RTP of 96.8%, low volatility, and a max win of 3,905x your stake,  it’s ideal for casual or strategy-minded players rather than high-roller adrenaline seekers.