thisisnotaspoon
If someone opened the sluices then there’s a danger of being sucked down and trapped, but I’m struggling to see the danger otherwise. There’s spillways which sometimes run in a pipe/culvert too but those are above the water level and upstream of the locks not in the lock itself usually.
Googles not throwing up many results for police divers drowning recovering bodies either.
Even when the sluices are closed, there’s usually some leakage. In the case I mentioned the sluices were closed IIRC, but the current was strong enough to pin them against the inlet. The second policeman died trying to rescue the first.
I doubt it would appear on Google, it was a long time ago, but iif you want to find it, try the Inverness Courier site as there was a commemoration ceremony recently. I knew one of the policemen involved, Ian Ritchie, a big strong lad and a very good swimmer.
There’s no second chances if you muck around near sluices. In the picture above, there’s water leaking through, so there would be fairly powerful current if you were on the other side.