Lake Ellesmere some pretty amazing spots, the best is Greenpark huts sandbar. Dan W and Mike have manged to sail there in some really good breeze and get some good speeds.
Greenpark huts is in the North Eastern Corner of the lake, where the Halswel River drains into lake. Getting down to the water can be a challenge, nearly got stuck last time I was there. It takes about 1hr to drive out there form home, but worth the drive when the conditions are right.
This speed strip works in both in the northeast (Our most common breeze) and the norwest. The north-easter easily has 10+ knots on any other spot around town, wind funnels down Lyttelton Harbour over Gebbies pass and is windier when it gets to the lake.
The spot is only waist deep when sailable, but often the wind literally blows all the water away. The wind can affect the lake level by +/- 1 meter, depending what side of lake you are standing on.
The other challenge we have is that the lake is mechanically opened to lower the water level to prevent flooding to surrounding farms.
It has been frustrating last few years with lake being opened in September October not enough rain to get it back to a level for us to use the sandbar.
We have been hoping for some rain to fill lake up a bit but because of how dry it is already this summer it might be March / April before we can sail here again. That time of year usually there is not as much wind around :(
I have only sailed here twice each time not very windy, but still managing to get my PB's for speed. I can't wait to give it a go on a speed board on some decent breeze.
I think a good sailor on here in the right conditions this spot has potential to get 45+ knots!!!