Tiona Park is split into two buy the main road, so theres a Surf side and a lake side.
Like Jethro said about lake side, and its probably a 200m walk through shallow
(calf to knee deep) water till you get to a sailable depth at the Tourist park. Not a big deal but you should be aware. If you drive further up (towards Forster) to the sailing club its sailable right from the shore.
Give a report when you get back! There are always newbs reading the forums looking for similar to yourself.