Aquatic Environments
Robots and drones are not often designed to handle prolonged exposure to an aquatic environment. The primary concerns that robots and drones face in aquatic environments are: interior flooding, crushing pressure, extreme cold and restricted modes of movement.
Interior Flooding
Although most are constructed with sealed robotic components to protect them from infrequent exposure to the elements or accidents, once the integrity of a robot’s hull has been compromised, a robot’s interior can suffer from exposure to an excellent conducting fluid: water. The energy produced by a robot’s own power plant can lead to its own demise, as the power short-circuits interior systems.
Once a robot’s hull becomes compromised (such a taking a hit to the Hull during combat or through other dangerous circumstances), water can flood the robot’s interior. If a robot is partially immersed in water (at least 25%), it takes 1d6 points of damage per minute of exposure. Robots or drones that have been completely submerged under water take 2d6 points of damage per minute. This damage bypasses armor, and is resolved like any other vehicle damage, per the Vehicle Damage Table in the Traveller Main Rulebook. Note that interior flooding does not cause Hull or Structure damage, and so any results of that nature (including striking a system that has already been completely disabled or destroyed) instead call for a reroll on the Location Table. Optionally, the Referee can determine that a result that causes only Hull or Structure damage is simply ignored.
A robot or drone with a Self-Sealing hull does not suffer from interior flooding, nor do non-robotic vehicles. (The occupants of a vehicle may have issues with interior flooding, particularly if they are not of a species that can breathe underwater, but the vehicle itself typically is not damaged by immersion. Electronic components, on the other hand, may suffer, at the Referee’s discretion.)
Crushing Pressure
Robots and drones, like vehicles in general, can handle greater pressure ranges than organic creatures. However, there comes a point where a robot’s structure makes all the difference in withstanding the crushing pressure of the deep ocean depths. The average robot, drone or vehicle can handle pressures of up to 200 meters before beginning to suffer the effects of crushing pressure. For every additional 100 meters below the safe limit, the robot suffers 1d6 points of damage per minute of exposure. The number of dice is reduced by the current Structure of the robot or drone. This damage bypasses armor, and is resolved like any other vehicle damage, per the Vehicle Damage Table in the Traveller Main Rulebook. Unlike flooding, crushing pressure can cause Structure and Hull damage. As the robot or drone suffers damage to its Structure, its ability to reduce the number of damage dice for crushing pressure is reduced. Once Structure begins to suffer, it’s a downward spiral toward destruction.
A robot or drone with a Reinforced hull has higher Structure and Hull values. The higher Structure provides more resistance to crushing pressure.
A robot or drone with the Aquatic hull design are essentially immune to crushing pressure damage, as the pressure is distributed. However, sudden changes in pressure may cause damage before the internal systems can compensate and distribute the pressure. When travelling upward or downward through the ocean depths more than 200 meters, the robot or drone must stop for a minute every 100 meters to acclimate to the new pressure or suffer damage every minute equal to 1d6 points of damage per 100 meters change in depth since the last time the robot or drone was acclimatized.