The problem you have to overcome is if your exhaust from the engine is
mixed with the water output. If it is you can blow your engine up by creating
substantial back pressure by attempting to send the exhaust down the hose
to where you are attempting to move the sand.
I had two 90 hp Yamaha jet drive outboards and we had aluminium manifolds fabricated
with two 3 inch elbows with male cam lock quick disconnects and a two inch aluminum
exhaust in the middle plumbing away the exhaust - so it wasn't mixed with the water pressure
lines.
I will try and find an old photo