Hello and Welcome..My name is XXXXX XXXXX Im sorry to hear of your troubles...What has most likely happened then here is that the engine has sucked copious amounts of water into the engine - via the air filter tubing - through the manifold and into the cylinders - so the cylinders are full of water - and that is locking the engine...so you cannot turn / start it.What will have to be done is to get the water out of the cylinders- this can be done by removing the glow plugs and then with them out - and out of the way cranking the engine so that the water flies out of the glow plug holes until the cylinders are dry - no more water coming out. The plugs are then refitted - and the engine will all being well , start. It should start and run ok - it may be a bit spluttery to start but should clear. So long as its not caused any physical internal engine damage you will be ok - but there is no way to tell that until you get it up and running - as above.. So thats the way forward on this one now..
You should find that the battery is not actually flat and should be fine.. If not - after getting the water out ( and checking the pipework etc is clear ) - re charge the battery and retry it.. it should be ok then.Let me know how you get on and I will get back to you if you still need..Kind Rgds - MIKE..................Please do click on the "OK/ Excellent ratings" for me as that's how Im credited for helping you - Thank you in advance for that...You can and are most welcome to get back to me anytime you might need - clicking the OK ratings does not close you out at all..Rgds, MIKE.