Not crass at all! :). First time I went back, I had a long fishing landing net, and tried sweeping as close to the bed as possible. Stirring up loads of mud in the process in already murky stretch. Decided to go back next day with same net and waders a friend loaned me. He also stuck a life jacket jobbie which would trigger when wet…it triggered when I slipped and accidentally went deeper! 
. Some comments have said the canal is only 3-4 feet deep. I have to disagree through this experience! 
It may be as deep as 6 feet with some really thick mud down there. And plenty of rocks under foot. My friend was there throughout, had me tethered to a really strong fishing line if I got in trouble. TBH, my biggest problems would have been the waders filling with water (potential disaster, even in a not too deep waters) or getting foot trapped between rocks. Or, I suppose to be really fanciful, a pike might have taken a chunk out of me! I certainly wouldn’t advise anyone to emulated all this!
Sadly, no light could penetrate the murkiness…
I was in there up to my neck! Not a thing I’m keen to do again, but wanted to give the wee guy my best shot at retrieving him. Sadly, he’s still down there somewhere, like the wee boy robot in AI…
With my glass half full hat on, that’s a damned sight cheaper than having to buy a new Mini 4 Pro from the shops 
Have a word with Scottish Canals then 
This is the quoted maximum dimensions.
Union Canal and The Falkirk Wheel:
- Lock length: 21.3m (70ft)
- Width: 3.5m (11ft 6in)
- Channel depth: 1.06m (3ft 6in)
- Maximum headroom: 2.7m (8ft 10in)
Thats a minimum for the falkirk wheel i guess.
An epic piece of engineering for sure and on my list of places to visit.
I know canals can go from almost wading depth to too deep to touch the bottom without messing up your do.
Also the currents can be plan evil downstream of locks and such. Depending on how well you fairin the water, i’ld almost go so far as to call some places lethal.
Did you look at your flight logs for any control anomolies, or was it definitely your input that put paid to the wee beasty? 
I shouldn’t have been in there anyway!
UPDATE:
After a number of attempts to retrieve the little fella, I bit the bullet and contacted DJI Care Refresh. I fully expected the drone to be classed as a “flyway” and was ready for the £219 charge. Did DJI not ask to see the flight logs, then after a few days said it looked like the drone took a wobbly and I would be getting a free replacement. It’s here now! Really can’t fault DJI for this episode, well done!
That’s excellent!
That’s fantastic news @GeorgeFalconer 
Another example of DJI going way way above and beyond with their Care service.
Both, my personal experience and those i’ve heard of..
They even call a few days after to confirm everything is in order.
