The technology relates to techniques for an aquatic energy discharge system for an energy storage system of an aircraft. An aquatic energy discharge system can include an energy storage system, a pair of electrodes coupled to the energy storage system, and a water detection system configured to detect a water landing. The electrodes can be configured to submerge in a body of water after the aircraft has landed in the body of water, and cause a hydrolysis reaction that drains energy from the energy storage system in response to the water detection system detecting the water landing. A method of discharging an energy storage system of an aircraft can include detecting that an aircraft (or portion thereof) has landed in a body of water, and discharging the energy storage system by powering a hydrolysis reaction using a pair of electrodes.