It could be older than that -
http://www.nzmeccano.com/image-39012 70 years ago was the middle of WW2, and any metal available would be going into munitions and bully beef tins. The images on the site in the link show early 1930s. All toy manufacture ended in 1942, and the boat range might not have resumed post war.
Theres plenty of information around regarding the construction sets, railways and Dinky die casts, but precious little about their boat range. Maybe they were mostly short lived due to water and clockwork not mixing well?
It seems that after a half century of troubled finances and confusing buy-outs involving mostly the US and the French along the way, part of the company now resides with Airfix, the rest with Nikko.