Corgi introduced it's popular Batmobile model in 1966. The following year they released their Batboat based on the Glastron Industries design for the 1966 film Batman.
My gift set 3 is a later edition first released in 1976, which also saw the altered version of the Batboat. (Mine has a repro box. The original would have had a polystyrene insert.)
While the first version of the Batboat came with figures of Batman and Robin, this one didn't. The beacon cage was also missing, even thought it shows it present on the box photo. There's also much cheaper decals. All part of cost cutting on Corgi's part.
The Batmobile had gone through a few changes over the years, too. The most obvious thing are the missing red bat wheel hubs. The Whizzwheels that replaced them meant the moving rocket exhaust at the back was now static.
Even though both these of these models have been altered to keep costs down, they still look pretty good to me.