There are a lot of new rules and regulations issued by IMO and Authorities to ensure safer shipping. However, safety at sea depends on many factors. The last but not least is the good knowledge of professional maritime English. This knowledge is significant at all the stages: during the ship design, construction and operation. Poor English will always cause problems; a badly written Contract or Specification can be the reason for costly misunderstanding and troublesome delays. How can we expect a proper operation of complicated systems and devices if their technical manuals are difficult to un- derstand? We believe the improvement of professional marine English in design offices, shipyards and onboard ships is a very important factor of maintaining safety at sea, and this dictionary was intended as our modest contribution in this huge task.   The terms in the dictionary have been carefully selected and checked. However, nothing is perfect and we would be grateful for any corrections or suggestions on how to make it better. The new, up-dated and revised version contains the enlarged “classic dictionary” section including the list of acronyms and abbreviations, as well as a picture dictionary of 146 full-colour pages.