RE: Starboard equivalent for HiFly Mambo
I think whether the Starboard GO 155 (255 long x 85 cm wude) or the HiFly Mambo (275 long x 80 cm wide) is going todepend a great deal on the skill levels you are teaching.
If you are teaching new beginners, the Mambo (or the Starboard Rio or Start M) will prove to be much better as beginners usually depend on the center board to keep the upwind.
If you are teaching more advanced students with all the basic skills already mastered (balancing on the board, uphauling, beachstarts, getting underway, tacking, basic jibes, planing a little, and staying upwind without a centerboard or daggerboard, then the GO 155-170 will prove to be alot more popular with your students.
The GO boards will plane earlier (due to the additional width) and have a significantly better overall range of use.
Hope this helps,