Everything is speculation at this point. Hard fact, they are out of touch and have been. This will either end badly or they will make a movie out of it.
Even if they wanted to use the USN DSRV out of San Diego it would take a while to get it to North Island, onto a transport, fly to Canada, put on a ship and chug out to where they believe the missing sub is. Even with 60 hours of air left it seems kind of bleak.
bob
Added info, USN DSRV is only good for 5000 foot depth (published).