Ouch. Don't panic though. take all the glow plugs out, and keep barring it over. When it has gone around 4 times, crank it with the starter, before putting the glow plugs back in. If you have the time/tool/talent, do a compression test. The water is most likely in the back two cylinders. Take the intake screen off and suck what you can out with a shop vac. I had water in Lady Moose from the same cause as your experienceing. The water collects on top of the air cleaner, and runs down the bolt that holds it on. That washer on top has got to be good to seal. I got that water out, and have had no issues with it. It's all going to depend on where the crank was when the piston ran out of travel. If the angle was a good 90 degrees, then the presure exerted will be much less than if the piston was near TDC. That's a connecting rod bending situation. If you get it turning, and put it back together, pray it doesn't have a lope or a miss. You could get lucky.