There's been increasing interest in autonomous service vehicles (ASV) and the USN Sea Hunter appears to be the most advanced and complex of the lot. It is claimed this “robotic ship” will be able to "operate in open seas over thousands of kilometres for months at a time” as it searches out opposition submarines in littoral waters. It will also be extremely advanced with "autonomous compliance with maritime laws and conventions for safe navigation, autonomous system management for operational reliability, and autonomous interactions with an intelligent adversary.”
Canada is also interested in a smaller more limited variant focusing on mine countermeasures that will probably be launched from a frigate according to the most recent Defence Acquisition Guide. Planned contract award is scheduled for 2021 just prior to the first Canadian Surface Combatant. One of the potential designs for the CSC is the UK's Type 26 frigate with a particularly large payload bay assumably for these types of systems.
One can confidently expect the roles for all these ASV, including Canada's, will continue to expand beyond ASW and mine countermeasures to include advanced warning of missile attack, electronic deception and surface warfare at the very least.
