Just another non-expert, but I wonder if the simplest approach might be to pump water under it to wash away the sand it's beached on.
Googling, it seems that this is a recognised technique for dredging: https://www.iadc-dredging.com/wp-content/uploads/2016/07/fac...
Whether it works might be dependent on what kind of soil its sitting on and whether the current is strong enough to take away the dislodged particles.
I guess it would also be hard to work out exactly what you've removed and hence whether you leaving the ship in a position that will stress its structure too much.
Googling, it seems that this is a recognised technique for dredging: https://www.iadc-dredging.com/wp-content/uploads/2016/07/fac... Whether it works might be dependent on what kind of soil its sitting on and whether the current is strong enough to take away the dislodged particles.
I guess it would also be hard to work out exactly what you've removed and hence whether you leaving the ship in a position that will stress its structure too much.