Anything you're remotely sending down there is going to be attached to a long wire and rather big. Also navigating tight spaces underwater can be challenging ev

Anything you're remotely sending down there is going to be attached to a long wire and rather big. Also navigating tight spaces underwater can be challenging even for a human, in person. Navigating them with a brick remotely is much harder. Some setups have smaller ROVs launched from another submersible, like ROV ROBIN.