Frederick Henrik at Chapman was a Swedish shipwright With an English father who travelled around the shipyards of England, Holland and France between 1750 and 1757. A book containing his drawings, 'Architectura Navalis Mercaturia', was first published in Stockholm in 1768; it is currently available as a facsimile edition. Figure 11 on Plate L is a drawing of an 'English hoy or lighter'.
I was looking for a small vessel to model as an entry to the Model Engineer Exhibition, and as a break from Myrmidon (a change is a good as a rest!). Chapman's hay fitted the bill, the drawing contained all the information needed for the hull and there was an outline rigging plan on Plate LXII.