As JW says the limit is defined by when you go vlock to block on your main, but before that happens you may find you've developed to much weather helm, making your boat hard to sail.

Sorry , yes Daggerboards ...TheMightyHobie18 ..... but how mach "little" mast rake ? where is the limit ?

Aside from the H16 trim application where you can vary the CLR, a heavily raked mast can help create a rollover vortex to delay separation on the low pressure side.

Cheshirecatman

Cooper, mast rake hanges a few things and as a result a full explaination is complicated. But the main reason it helps is to do with lift distribution.

with the mast upright the centre boards are providing most of the hydrodynamic lift that stops your boat going sideways. In order to develop this lift your boat must go sideways a little (leeway) so that the angle of attack of the symetrical foils is sufficient to generate lift. If you rake your mast back then the cntre of effort moves aft so that now the rudders are also being asked to supply lift.

by splitting the load between the boards and rudders you have reduced the amount of lift required from the centre boards and therefor the amount of leeway you'll need to generate said lift. As a result you'll point higher.

As JW says the limit is defined by when you go vlock to block on your main, but before that happens you may find you've developed to much weather helm, making your boat hard to sail.

A-class cats with their highly efficient and very vertical masts would disagree with the vortex theory.

Scarecrow's explanation is as technical as needed for improving upwind performance. The trick is finding the right balance for fastest times around the course. Balance of lift to drag as well as upwind and downwind performance.

..... as imagined, there isn't a definitive solution.