There are about four hundred Units in the Sea Cadet Corps, spread all over Great Britian and Northern Ireland.

The Units are grouped into Districts, each containing between six and ten Units depending on distances; Each District is named (eg Sheffield is in South Yorkshire and Humberside District) usually based on the geographical location.

The Districts are grouped into Areas, of which there are six, each one containing between 60 and 75 Units and with a small Royal Navy staff. These Areas are controlled by The Commodore of The Sea Cadet Corps, from Sea Cadet Headquarters in London.

About 75 Units have Marine Cadet Detachments (Sheffield being one of these) whose training is based broadly on that of the Royal Marines and laid down in Marine Cadet Training Syllabus.

Activites in the Sea Cadet Corps

The subjects laid out below are compulsory for advancement up the ranks, they are all taught onboard TS Sheffield as part of normal cadet training:

The following activites are also arranged by the Unit for cadets to undertake to further their training:

Cadets can also choose to specialise in various subjects for which training is carried out on a regular basis. The following Specialisations are avaliable either at the Unit or at other locations.