Blue is best.

DrRobin wrote:

the diff and TC breathers (which are 300mm) although should seal, but might let a little in if they were hot/open when you entered the water
 

The diff & TC breathers are essentially one way valves, opening only when the pressure in the diff or TC exceeds atmospheric - how water gets in is through the axle seals, when the pressure inside drops below atmospheric because the warm axle has been suddenly cooled.  The axle seals are designed to keep the contents inside rather than prevent whatever is outside (usually air) from getting in.

Extended breathers allow an unrestricted flow of air in both directions.

lightning wrote:

l didn't realise the Jimny only has a 12" wading depth.

My 2022 Defender had a maximum wading depth of just under a metre. l wouldn't like to test it out, although l've seen Youtube videos.
The problem is, if you stall in water that deep there's a good chance your vehicle will be a write off.
Okay for motoring journalists maybe.

 

The limit for mine is 6", which is just over the wheel rim (at the bottom!!!). I'd rather spend 2 hours and £10 finding a route round the water than 10 hours and £200 fixing water damage if it gets inside the hubs, brake drums & axles..  (I might chance another inch if it were clear fresh spring water, but definitely not if it was the brown raw sewage we normally get round here- then it is creep through at 0.01mph so as not to splash any up under the car)

I took the Series III through some deep muddy water once, probably over a metre deep from the tide marks on the body.
First thing that happened was it stopped moving when it floated and the wheels lost traction.
Luckily, being a Land Rover, it leaked like a sieve with holes punched in it, so as it gradually filled with water it sank enough to gain traction and drive out. I was so proud of myself and my extreme manly prowess at the time.

A week later, when I was changing the seized washer pump, screeching heater motor and failed alternator and cleaning out the starter motor I was somewhat less proud, especially when I could have just driven round the side like all  the wimps sensible people.



 

The new Defender seems unaffected by deep water within its limits. But at over £60,000 l would expect it to be capable.

The Jimny cost £20,000 which made it affordable to "normal" people. ln some cases it has been better off road than my new Defender, due to the smaller size and light weight. lt also has better visibility particularly when cresting a steep hill.