>>63986518
>>63979674

Laugh all you want, the future marine sensors may or may not be indefinitely fueled by "marine biomass". From sensors it will move towards drones or drone systems, until we have whale-sized energy harvesters charging smaller underwater combat drones, with energy delivery drones dropping batteries to contested areas.

https://www.spacewar.com/reports/DARPA_Launches_BLUE_Program_to_Power_Ocean_Sensors_with_Marine_Biomass_999.html