technically, folks calling the jet nozzle a “thruster” are dead wrong-it’s a variable area nozzle modulating exit velocity per bernoulli, not vectored thrust like a bow thruster.
under the hood: q = 2500 gpm (0.09 m³/s) thru 4″ nozzle (a=0.0013 m²) at 55 psi backpressure gives v_exit ≈ √(2Δp/ρ) = 28 m/s. buckets in reverse dump it forward at 15 m/s effective. no magic, just fluid dynamics. your “instant reverse” is just high inertia losses.