The JACRIM Manufacturing Co. was the brainchild of Chester Rimmer and Arthur Jackson. Two graduates of the class of 1921 at MIT. Around 1922 company was started with $10,000 from Jackson’s uncle Charles H. Jackson. The first official registration with the state of Massachusetts was in 1924 in the city of Malden. There is no record of Seaworthy boats and it was probably a trade name. Rimmer was listed as treasurer and his other brothers were the other officers. The older brothers were coopers and cabinet makers by trade and probably had some money. There is no mention of Jackson and he left the company to pursue engineering about 1925 This was caused by the company take over by Keystone Manufacturing.  Isadore Marks was now President and Benjamin Marks was Secretary. Chester Rimmer remained as Treasurer. The other Rimmers took jobs in other Marks companies. The boats were mostly hand crafted and they soon left Malden for 288 A Street in Boston.  After 1934 the boats were then marked Keystone.

As keystone production increased and hand shaped boats gave way to machine cut, many Seaworthy features were eliminated. Mostly for cost cutting. The product line was 12” to 36” Sailboats, spring motor driven Motor boats from 18” to 30”, Battery boats, rubber band driven boats, Tom Thumb boats, Forts, Doll Houses, Furniture “Ride Em:” wagons and other toys and then by 1938 the war toys appeared and continued through the 40’s. The production continued through 1957 and Chester Rimmer Retired. This web site will be devoted to boats.