dechucka
2008-08-18 23:31:55 UTC
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
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