Deep Sea Adventure — Rules, Oxygen & Strategy

Setup: treasure path and 25 shared air

In the original Deep Sea Adventure by Jun Sasaki and Goro Sasaki, the group uses one submarine, six available diver pawns, 32 treasure chips arranged into four levels of value, 12 blank chips, an air marker and two dice numbered 1–3. It supports two to six players and takes roughly 30 minutes.

Put the submarine where everyone can reach it and set the air marker to 25. Sort treasure chips by their level, shuffle within each level and make a winding single-file trail going from lower-level treasures near the sub to higher-level treasures farther away. Keep all printed treasure values facedown. Place every diver on the submarine. The player who most recently swam in the sea goes first according to the original English rules.

Every turn has four steps

1. Breathe: reduce shared air by the number of treasure chips you currently carry.
2. Choose direction: if you have treasure and are still going deeper, you may turn around toward the submarine.
3. Roll and move: roll both original dice and move their sum minus the number of chips carried.
4. Treasure action: pick up the treasure where you stop, drop a carried treasure on a blank space, or do nothing.

Returned divers take no more turns during the current dive. The breathing cost applies at the start of each active diver’s own turn based on that diver’s carried chips, not as one automatic deduction of every player’s treasures between turns.

Shared oxygen: worked example

Everybody uses the same air marker. Suppose the air track is at 17 when your turn begins and you are carrying three treasure chips. Move the marker to 14 before deciding whether to turn back and before rolling.

If the next player is carrying two chips, that player’s turn reduces air from 14 to 12. A diver who carries none reduces the air by zero. This is how one player’s extra treasure can endanger everyone else.

When air reaches zero: the active player still finishes their turn after the air reduction. The dive then ends, so any divers who have not returned to the submarine lose their carried treasure. It does not create a free extra turn for the whole table.

Dice movement and treasure weight

Roll two original dice, each showing one, two or three dots. Add the results, then subtract one movement point per treasure chip carried. If the result is zero or negative, you do not move. The minimum movement is not automatically one.

Example: your dice show 3 and 2, totaling 5. Carrying three chips leaves a movement of 2 spaces. Carrying five chips leaves 0 spaces, possibly making it impossible to reach the submarine until you drop treasure.

When moving, jump past spaces occupied by another diver without counting those occupied spaces. Movement follows the one connected treasure trail. If diving deeper takes you beyond its far end, stop on the final chip.

When and how can you turn back?

You may declare that you are turning back only if you carry at least one treasure chip. Rotate your diver toward the submarine before rolling. You may change direction only once per dive, so after turning back you cannot resume going deeper.

If you roll before announcing a direction change, you must continue outward for that turn. Turning back late risks running out of air; turning back early means sacrificing the chance to reach deeper, potentially higher-value treasures.

Once your movement reaches or passes the submarine, return there immediately and stop taking turns for the rest of the dive. Only treasure safely brought aboard contributes to your eventual points.

Picking up and dropping treasure

After moving, you may take the treasure chip on your current space and keep its value hidden, replacing that space with a blank chip. Alternatively, if you are standing on a blank chip and carrying treasure, you may put one carried chip down there. Or choose to do nothing.

There is no fixed carrying limit, but more chips consume more oxygen and slow movement. Dropping an item may be strategically important: carrying four chips and rolling 2+2 gives you no movement, while dropping one means that a future roll totaling four would allow one space.

A treasure’s printed value is revealed only once it has been returned safely to the submarine; face-down levels suggest relative risk and potential reward without revealing the exact points.

What happens to treasure after a failed dive?

A dive ends when all divers have returned or the shared air supply is exhausted. Returned players reveal and retain their treasure chips as permanent scoring points.

Any diver still below the surface loses the treasure carried during that dive. Starting with the stranded diver closest to the submarine, put their lost chips in stacks at the far end of the trail, up to three chips per stack. Later, a whole stack is treated as one treasure chip for moving, carrying and air consumption.

Remove blank chips from the trail and slide the remaining chips together to remove gaps. Reset the oxygen track to 25 and return divers to the submarine for the next dive. Treasure safely banked in earlier dives stays with its owner and does not affect future air consumption or movement.

How the winner is decided after three dives

The original game always contains three dives, unless your group agrees on house rules. After the third dive, total the printed values of all treasure chips you successfully returned across all dives. The player with the highest total value wins.

If scores tie, compare the number of treasure chips from the deeper, higher-value levels, following the rulebook’s tie-break criterion. If the tie cannot be broken, those players share the win.

Example: one player safely returns treasures valued at 4 and 7 on the first dive, nothing on the second, and 5 on the third. Their total is 16 points. Unreturned chips never contribute points.

Classic Deep Sea Adventure vs Deep Sea Adventure Boost

The 2024 Deep Sea Adventure Boost is an enhanced version featuring extra movement options. The original game uses two dice numbered 1–3 and does not have a Boost action.

In Boost, players roll three specially marked dice and normally choose two results for movement. They can also declare a Boost, spending additional shared air to use all three. Boost includes the original two dice, allowing its box to be used with classic rules.

The same broad decision remains—risk the communal air for deeper treasure—but a Boost-specific strategy article should account for the extra die choice and air-spending action. This guide covers the original rules unless explicitly labeled otherwise.

Nine strategic principles for the original game

• Calculate your return distance. Being far down the trail with several chips is much more dangerous than having the same distance with an empty hand.
• Monitor everyone’s carrying cost. The shared air can vanish quickly when several players haul treasure.
• Turn around early enough. Direction changes are one-way; do not wait until the air track is already near zero.
• Remember the dice cap. Original rolls total 2–6, so six carried chips prevent movement entirely.
• Consider dropping treasure. Sacrificing one unknown-value chip can restore movement for a safer escape.
• Look for occupied spaces. Other divers’ positions are skipped when counting movement, potentially changing how far your roll carries you.
• Value banked treasure. Chips returned in one dive are safe and do not burden you in later dives.
• Understand stranded stacks. A stack of up to three lost chips becomes a single carrying item in a later dive.
• Adjust in the final dive. A trailing player might need to seek riskier depths than someone already leading.

These suggestions are original, rules-based analysis, not a claim of personal playtesting.

Deep Sea Adventure FAQ

How many players can play?

Two to six.

How many dives are in a game?

Three.

How much oxygen do you start with?

25 on the shared track at the start of each dive.

How much air do I use?

One point per treasure chip you carry at the start of your turn.

Does the original game use three dice?

No. It uses two 1–3 dice; the three-dice choice belongs to the Boost edition.

Can movement become zero?

Yes. Subtract carried chips from the dice sum; you might not move at all.

Can you turn around before collecting treasure?

No. Turning back requires carrying at least one treasure chip.

Can you turn around twice?

No. One direction change per dive.

When do treasure values become known?

When the chips are returned safely to the submarine.

What happens when oxygen reaches zero?

The current player completes their turn, then the dive ends; divers still underwater lose the treasures they carry.

Do stranded treasures disappear?

No. They are stacked at the far end of the path for later dives.

How do you win?

Bring back the greatest total treasure value over three dives.

Who should play Deep Sea Adventure?

Best for 2–6 players who enjoy shared tension, simple dice decisions and trying to judge when a reward is worth the risk. The communal oxygen creates indirect interaction; anyone seeking predictable, low-luck planning may prefer another game.

Similar games and what to play next

If you are comparing this game with other titles on BoardGameArchive, these guides explain genuinely different mechanics and player experiences:

• Incan Gold — The closest thematic comparison: both are push-your-luck expeditions where turning back protects treasure.
• Spots — For another approachable push-your-luck game, Spots relies on dice and personal risk rather than communal oxygen.
• No Thanks! — A short card alternative built around evaluating the cost of taking another risk.

Sources and editorial scope

• Oink Games official Deep Sea Adventure product page
• Original Deep Sea Adventure rules text
• Original English rulebook download
• Oink Games: Deep Sea Adventure Boost edition differences

Rules checked October 12, 2026. Examples and strategies are original editorial explanations, not claimed personal playtesting. Original and Boost mechanics are clearly distinguished. Editorial policy and corrections.