Moonbeam IV was laid down in 1914 but wasn't completed until 1920.
William Fife junior had introduced composite construction into the family yard in 1891, having learnt the technique at J Fullerton & Co at Paisley. Moonbeam III was built the traditional way, but Moonbeam IV had steel frames with Burma teak planking. 90% of the structure is still (2018) original.
On first seeing her in 1920 Uffa Fox said 'No matter whether she is under way or at anchor, Moonbeam is beautiful to look upon and, combining the speed of a racer with the comfort of a cruiser, is a vessel any seaman would be proud to own'.
The photo below shows her in the foreground with Moonbeam III behind.