Nothing down at Smiths Lake but i have seen one of the Boats sheds on little street in Forster rent out X-trainer sups.

FORSTER AREA - A great area to paddle but currently no one servicing anything in hire. Jungle Surf in Tuncurry sell new boards and they would be the best bet to see if they have something to hire. Joey at Iguana Surf in the main street of Forster is one of the main paddlers up there and he's always happy to give you directions.
The boat hire place opposite the pub has a couple of old boards which you can take out the front of their shop.
Lots of great paddling and I paddle with dolphins every time I paddle from the entrance down to the island airport.
SMITHS LAKE- The Frothy Coffee hires Canoes and might be an option.
SEAL ROCKS - nothing unfortunately.

Your best bet would be to go and see someone in Sydney and take a board up with you. If the surf is small the place is an unbelievable flatwater paddle spot.

Thanks guys so much for your help! Will check it out :)

Why not hire one before you go for the weekend and take it with you then you will be sure to have a board for Dad and you can both enjoy the sytoke.