99. (1) Subject to the provisions of sub sections (2) and (3), no young person shall be engaged or carried to sea to work as a trimmer or a stoker in any ship. (2) Sub section (1) shall not apply-(a) to any work of trimming or stoking done by a young person in a school ship or training ship in accordance with the prescribed conditions; or(b) to any work of trimming or stoking done by a young person in a ship which is mainly propelled otherwise than by steam; or(c) to the engagement of carrying to sea of a young person over sixteen years of age to work as a trimmer or stoker on a home trade ship or coasting ship in accordance with the prescribed conditions. (3) Where in any port a trimmer or stoker is required for any ship, other than a home trade ship or coasting ship, and no person over eighteen years of age is available, two young persons over sixteen years of age may be engaged and carried to sea to do the work which would otherwise have been done by one person over eighteen years of age. (4) There shall be included in every agreement with the crew in ships to which this section applies a short summary of the provisions of this section.