You must be a UK resident or have UK right to work.
You must also have:
Right to Work in UK
Passport
COC/COP Able Seaman
Crane Operator Level 3
STCW safety training (PST, FPFF, EFA, PSSR)
STCW seafarers with designated security
BOSIET/FOET with CA_EBS
ENG1 Medical
Shoulder Measurements
Seamen's Book