A dorky accountant has to overcome his fear of the ocean and learn to surf in order to attend a father-son surf competition so his son can hang with the cool kids, one of whose dads just so happens to be his high school nemesis.

You shouldn't, its your idea! :)

Thanks patrockable, that really tightens it up... I feel guilty running with that now, it's like you've done all the work!

Yeah, I think acceptance is relatable enough!

Here's my take:

An ocean-fearing accountant must beat his high school nemesis in a father-son surf competition to earn his son's respect.

Thanks.

I agree that it's too verbose...

Stakes... well, the real stakes are to get his son's acceptance. That's stronger than his son hanging with the cool kids... but not sure if it's strong enough.

The concept is intended to be a light hearted comedy... so I might try and steer clear of terminal illness!

I think you need a bigger stake than 'help his son hang with the cool kids'.
Also, it can be considerably cut down to read more fluently -

A regular dad must overcome his fear of the ocean, as well as beat his high-school nemesis, in a surf competition whose prize will save his son from a life-threatening illness.

Maybe?