Hi, Just doing research into a freeride setup for beginner/intermediate to suit boggy lake. I'm 85kg. No budget

Does anyone know average windspeed for boggy, as I can't find much info.. seems to be around 12/15knots, correct if wrong

I'm checking out the bic techno 148 as its foil suitable, but not really sure ay. One website says I need a sail of 7 - 8m2 for 15kn winds.... seems huge to me.. www.surfertoday.com/board-size-chart/windsurf

thx in advance