21A.11.1 There must be at least one set of sanitary
facilities for each 6 seafarers onboard, separated from the rest of
the accommodation. Each set of sanitary facilities should include
one shower or one tub, one wash basin and one toilet. Each set of
sanitary facilities must be provided with a door that is lockable.
Where reasonable and practicable there should be separate sanitary
facilities provided for men and for women.
21A.11.2 In vessels where a sanitary system, including
a holding tank, is provided, care should be taken to ensure that there
is no possibility of fumes from the tank finding their way back to
a toilet, should the water seal at the toilet be broken.