Using SUPracer's Top 14 Most Competitive Races of 2014 as a guide -
www.supracer.com/top-14-most-competitive-races-of-2014/ - if we exclude the events that have fallen over this year (BoP, Ultimate SUP Showdown, a number of World Series events) and we assume PPG will become the new number one most competitive race...
Taking all that into account, the 10 most competitive races of 2015 may well end up being:
Pacific Paddle Games Elite Race - 14'
Pacific Paddle Games Distance Race - 14'
Columbia Gorge Paddle Challenge Course Race - 14'
Columbia Gorge Paddle Challenge Downwind Race - 14'
Carolina Cup - 14'
World Series Finals Turtle Bay - 12'6"
The Lost Mills Distance Race - 14'
The Lost Mills Sprint Race - 14'
Molokai 2 Oahu - Unlimited
Maui 2 Molokai - Unlimited
Now, I may be wrong*, but as far as the men are concerned, that's 7 races on 14', 2 races on Unlimited, and just the world series final event on 12'6".
* I just took the board lengths from SUPracer's 2014 information - events may have changed in 2015.