During World War II Royal Enfield participated in a variety of non motorcycling projects. Among them was the construction of a two cylinder "boxer" liquid cooled diesel engine, popular for generators. Later an air cooled diesel was built, apparently one of the first in the world. The division that carried out these projects was the "Enfield Industrial Engines". The E & H P Smith group took over Royal Enfield in the 1960's and started breaking up the company. Enfield Industrial Engines was sold to a greek shipping millionaire John Goulandris and relocated, including workers from Redditch, to the Isle of Wight. The company was involved in various projects, including the production of the Enfield Electric Car, the first modern production electric car! An amazing story is that as recently as 2007 there was talk that the Enfield Electric could make a comeback! The company later relocated to the greek island of Syros, and went by the name of Enfield Automotive. There are groups of enthusiasts for these vehicles, as expected.
I could not find if the Isle of Wight company exists today. One can find online some patents dated in the late 1970's awarded to the company. A site listing UK businesses claims the company does not file papers since 1983. In the book by Anne Bradford, Rex Wearing is quoted as seeing the factory with a sign saying Enfield Industrial Engines in 1993 on vacation in the Isle of Wight. The address corresponds to a well maintained set of buildings today, but there are other companies with the same address.
The Isle of Wight company produced powerboats in the 1980's that won many races including one called "Miss Enfield 2" and another called "Enfield Avenger".