Humans have been building multistage gas turbines for 90 years and they are progressively smaller and lighter. Whatever powers this it's probably not much more than a dozen vacuum cleaner blowers, or maybe leaf blowers; 15 years ago something the size of a coffee can provided 70lbs thrust (measured on the ground probably, might be more like 40 in the air but a dozen 2 stage axial or radial turbines I said)
I think I can easily convert some cheap power tool into a fast winch and then throw a line to another boat and have something like water skis or a surfboard and do the same thing with greater survivability rate and 1% or less of the power budget, man-hours and funding
Battalions of these guys with shoulder mounted rocket launchers hovering over the skies of war torn cities...We really need to stop war-making so fucking cool!
I haven't tried these guys out yet, so I can't decide if they're better than just traditional jet pack assault marines or assault intercessors. Chapter approved! https://warhammer40k.fandom.com/wiki/Inceptor