planning threshold of 8.0 & formula

[mike]

Hi Roger,

My present big rig is a 135L freeride (JP X-cite) & 8.0 Retro. I'm 185lbs. I figure my minimum wind requirement for this is 12 knots. This is decently powered, generally relaxed sailing. I may be able to continue nursing a plane through a bit less (lulls) but not so fun.

I have long debated whether or not to go formula. If I did I would start with the board and maybe get the 10.5 (& mast & boom) in the future if I choose.

My question:

What would be my estimated planning threshold for, say, and 158L F-type and a 8.0 Retro? Say the number is 10 knots average. Would this be nicely powered or would I be working?