Designed by John Powell and built in 1956 by Aeromarine in Emsworth, where Powell was the yard manager
She was solidly constructed with 1¼" teak planking on English oak frames and Canadian rock elm timbers with fastenings in gunmetal and Crotorite (a copper-manganese-iron alloy), with an oak centreline and teak superstructure
She had a Foden 70hp two stroke diesel engine with tank capacity to give her a range of 560 miles at 9 knots, and a sail plan which included a steadying mizzen and a genoa intended for occasional off-wind sailing
She had a 1½ tonne lead keel which was moved forward a couple of feetsoon after she was built because she was trimmed down by the stern
Although she had the appearance of a work boat, she was built as a yacht, and was named after Guthrie's mother