"fast, zero-emission delivery"
cynic in me says: there's never been better times than now to promote ideas of ZERO! EMISSION! DELIVERY! no matter whether realistic (do they have . And, on a less cynical note... why would you run cargo in underwater mode which, presumably, requires a lot more power to push through water, rather than to push 'a bit of it' through water, i.e. surface? Yeah, they mentioned, adverse weather condition, but still... unless we're trying to invade Ireland or France (again) - 'in secret'?!