> Next door neighbour stupidly dropped his car keys into his farm dam while
> out on his kayak. Knowing I was a diver he asked if I could try and find
> them. OK we are 670m but I have dived at higher altitudes and the dam was
> only 7-8ms deep so no problems.
>
> Interestingly the water temp at the surface was about 5C and than I hit a
> distinct thermocline at 3ms and the temp was 8C. Surely even with not much
> wind the colder heavier water should sink below the warmer water. The dam
> in question is quite large probably 1/2 a hectare and has got good inflow
> from a small stream. Wondered how the warm water could sit on the bottom
> even knowing that Sydney's bad smog is caused by an inversion layer where
> cold air traps the warm air and pollution in the basin.
>
> Anybody else experienced this and any theories on why it can happen
>
>
> PS I soon got out of the water without his keys, far to bloody cold and he
> can afford some new ones. Only had a 5mm Farmer John with hood