Hi Martin,
When I did one of my Sailing Seminars in Munich in late April it was pretty neat sailing in front of the snow-covered Alps. Temps were pretty nice, but the water was VERY, VERY cold. And the lake was extremely deep. And I was recovering from a hernia operation.
So, instead of letting out 150' or more of anchor rode for each mark, I just put the marks in without anchors. Funny, they all drifted relatively at the same speed. That kept me from freezing my hands, tearing up my hernia, etc. while hauling up hundreds and hundreds of line.
But, it was beautiful.
Rick