In a major SHTF disaster, motorized travel of any variety will be unreliable at best. Between gov restrictions on airspace, roads, and piers, and crazed mobs assaulting anything they think will get them out, this Plan B service sounds iffy. It’s probably going to be Shank’s Mare, or if you’re in a very tall building close to the river you might be able to arrange a cannon-fired zipline to at least get across the water. Other than that, I dunno. Maybe Doc Savage’s old pneumatic tubes to get to the waterfront, but they supposedly went to the harbor side, not the river, which won’t help much.
Between gov restrictions on airspace, roads, and piers, and crazed mobs assaulting anything they think will get them out, this Plan B service sounds iffy.
There simply are not enough government forces available on a moments notice to do all that you suggest.
Sending someone to man the boat at the news of a disaster would be an obvious course of action.
As an aside, a considerable number of engines are *not* susceptible to EMP pulses.