Dr Terence Harrison, the likely successor to Peter Usher, said pressure of other work, notably at the aero engine maker Rolls-Royce, meant he could not continue.
Mr Usher, who led the management buyout and flotation of Vosper, said he did not want to stay on 'for the hell of it' and hoped to find a replacement within a year.
The company saw turnover rise 22 per cent to pounds 239m in the year to 31 March. Although the order book was down pounds 200m to pounds 500m, Vosper was confident of winning at least one of three orders under tender. This includes a possible order from the Royal Navy for further Sandown Class minehunters.
Vosper is one of the country's largest publishers of technical books, supplying information on its own ships and data on the aerospace and utilities industries.
A final dividend of 12.7p makes 18p for the year, up 14 per cent. The shares were down 1p at 778p.