The free endless dive trivia game where the rarest answer wins
Stage
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Founded
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Based in
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Pricing model
Freemium
Free
Pricing
Free: $0. Pro: $9.99/month, $69/year, or $149 lifetime (early-bird for first 100 buyers, then $249). Pro covers up to 100 Coach-explained games and 50 scoresheet photos per month.
Not given
Key features
Accuracy scoring based on winning chances
Move labels: inaccuracy, mistake, blunder
No account required for free review
Import games from Lichess or Chess.com
Coach written explanations in plain language
Scoresheet photo to PGN conversion
Suspected mistakes checked twice at greater depth
Seven prompts per dive with 25 seconds each
Six rarity scoring tiers from Plankton to One in a Krillion
Ocean depth visualization showing score as metres descended
Five real ocean zones from Sunlit Shallows to Hadal Trench
Unlimited mode for endless practice dives
Daily dive with same prompts for everyone
Multiplayer with pass-and-play or online rooms
Practice mode with no time pressure
Question bank with 172 hand-built questions
No account required; play as guest
What makes it different
Honest labeling: mistakes rechecked deeper before labeling
No uploads for free review: analysis runs locally in your browser
Free review never requires account or has daily limits
One-click review for returning users with remembered username
Rewards rare answers rather than just knowledge or speed
Never reveals answer lists to preserve mystery
Completely free with no premium tier or paywall
Score visualized as real ocean descent through five zones
Explain My Chess
Free Krillion