Thanks for your replies. I will definitely stick to the 800mm!!
On the door seals, perhaps I am lucky but if I don't have a window open, I need to close any door "with vigour" in order to latch the doors
If you think that you can actually increase a Grenadier’s wading depth by mounting a high snorkel, let’s remember that a vehicle with doors that seal means that the vehicle is a box that can become a boat.
So, a very very rough back of the envelope calculation show a Grenadier will actually float in water that is shallower than one would think:
Dimensions of a Grenadier’s enclosed cabin are approx. 123” length by 76” width. That gives you 9348 sq. inch for the floor area of cabin (yes, I know there is a raised center tunnel etc.)
Water weighs 0.036 pounds per cubic inch, and a Grenadier weights approx. 6000 pounds with a minimal load.
So, how many cubic inches of water = weight of the vehicle?
6000 lb / 0.036 lbs per cu inch = you need to displace 166,667 cu inches of water to float it like a boat.
So at what wading depth will enough of Grenadier cabin with its door seals be submerged in order to displace enough water to float the vehicle?
The required 166,667 cu inches divided by the 9348 sq inch floor area of cabin means you need 18 inches of water above the bottom of the cabin floor to float.
The Grenadier's ground clearance is 10.4 in, and if we assume the cabin floor is 8 inches above that (just guessing here), you need water that is 18 + 8 + 10.4 inches deep or 36.4 inch deep water.
BUT remember all those videos from this year’s flood: you will lose traction and the ability to resist cross currents way before that.
Why did the old Rovers and Defenders do better? Because the doors were not sealed and thus you could not trap enough water in the cabin to displace enough water to float it. (my old IIA had a fat screw mounted in a holder next to the clutch housing to insert and seal it if you were going to wade a deep crossing).
But a snorkel still looks cool.