The MAIB’s sole objective in investigating an accident is the prevention of future accidents by establishing its causes and circumstances:  it is not the purpose to apportion liability, nor except so far as is necessary to achieve the objective, to apportion blame. The MAIB is not an enforcement or prosecuting body.

Powers of inspectors in relation to premises and ships. (1) The powers apply to any United Kingdom ship wherever it may be and any other ship which is present in the United Kingdom  waters; and are available to any MAIB inspector, who (a) may at any reasonable time board any ship, if he has reason to believe that it is necessary for him to do so.

MASTER candidates need to read the below MGN.

MGN 564: marine casualty and marine incident reporting

Accident report form (ARF)

Accident Report Form