Well we didn't see everything even though we were there when it opened at 10am and didn't leave until 4pm!
The tickets you buy do last for a year, so although its doubtful we'd make the return trip due to distance, if you live close you could spend a lot of time there.
I did feel it was a shame you didn't have the option to buy a one day ticket at a reduced price to the annual ticket, ad like many people we won't be returning.
At £26 for an adult it is brilliant value for an annual pass but expensive for a day trip. I would still recommend it though.
The whole area is very well laid out, attractive, has plenty to do and see and lots of options for food at not too greater cost.
I had a brilliant day, make sure you leave time for the harbour tour and the three big boats, anything extra is a bonus.More