There is no way my mates 5'10 x 18 x 2 1/4 would ever be in my quiver. I can surf it just but don't see the point especially with all the other type of boards around. But I know my paddling is weak so had a thought. Would training by paddling up and down the beach on this little 5'10 be beneficial? Not to mention every now and then when a good one comes though, you could probably snag it.

If you want to get stronger go swimming at the local pool. Freestyle only. Interval training style.
Build up you laps and see how much your surfing improves.
If you still dont have good technique get a swimming lesson..

Dont bother with the 5'10, buy a more suitable board that is fun, and you will fing you get fit coz your more stokes and wanna surf more.

+1 for swimming to strengthen and improve your paddling.

check out John Konrads Swim Easy DVD. He was a Aussie Olympian.

I broke my back 14 years ago and had to do a lot of swimming for rehab. After 20yrs of regular surfing I was surprised how bad at swimming I was. Mate gave me this vid and I spent some time working on the techniques shown. I went from not being able to swim 100m continuously to swimming 3km non stop in a matter of about 10-12 weeks. It's nearly all technique. Years later and without the fitness I once had I can still do 1.5km non stop at a reasonable pace.

Once you get the technique right then interval sprints will build your power.

I have an old VHS copy of this - but it was re-done and re-released on DVD last year. Worth a look.

http://johnkonrads.com.au/