Military crew are the technical specialists of the ISDC and receive applied technical training in their chosen professional fields right from the beginning of their careers. 

For crew, qualification is just as significant an indicator of seniority as rank. Crew with aptitude and experience can expect to become highly respected technical leaders in the ISDC.

Crew Career Tracks

A career as a technical specialist begins at the rank of Crewman. Crew will undertake common training, which covers fundamental technology concepts, the ISDC’s mission and how the ISDC works as an organisation.


Crew will be asked to choose a professional area (known as a branch) that interests them, where they will undertake technical training.

 Within each branch there are a number of specialisations, usually related to the operation of a vessel system. Crew will begin training on one of those specialisations with a view to becoming qualified to operate that system (or “rated” on that system).

Basic Rating

The initial qualification withiin a specialisation is known as a basic rating, allowing crew to operate that system on active duty. On achieving a basic rating, crew are promoted to Able Crewman and the insignia of their specialisation is added to their uniform.

Crew can attain basic ratings in a number of specialisations if they choose, qualifying them to operate a range of systems and giving them a better idea of which specialisation they’d like to progress their careers with.

Advanced Rating

After gaining experience and undertaking additional training within a specialisation, crew can be awarded an advanced rating. This allows crew to take on more senior roles including assignment to core watches, team supervision and becoming an instructor. Attainment of advanced rating is recognised with the addition of a badge to uniform.

Master Rating

A master rating is awarded on demonstrated merit rather than through a formal training program, to recognise extensive experience and professional excellence. A master rating places those who attain it at the pinnacle of their specialisation and is recognised by a gold version of the rating badge and the addition of the prefix “master” to rank.


The qualification system recognises the particular skills that crew have, while rank reflects the level of responsibility and authority held. The two are closely related. Crew with an advanced rating in a specialisation is likely to be given more responsibility (reflected by a more senior rank) within that specialisation.

Typically, crew attaining an advanced rating can expect to be promoted to Petty Officer (PPO). The most senior crew can expect appointment as a department chief, or technical lead for their specialisation on board the vessel. A department chief always holds the rank of Chief Petty Officer (CPO).