Explain detainable deficiency with reference to a PSC inspection?

Detainable deficiency:
A deficiency that presents an immediate threat to the ship, its personnel or the environment, which renders the ship unsafe to proceed to sea.

A ship can expect to be detained when in the professional judgment of a PSCO i.e he considered unsafe to allow a ship to proceed to sea before the deficiencies identified have been rectified.

EXAMPLES OF DETAINABLE DEFICIENCIES:
Under SOLAS

• Failure of main propulsion, electrical, pumping, and steering
• Excessive oil leakage in E/R, lagging insulation contaminated by oil
• Absence non-compliance or poor condition of LSA equipment, fire dampers, ventilation dampers, quick closing valves, etc
• Absence, non-compliance of poor condition of navigational lights, shapes and sounds signals
• Absence of corrected charts and publications
• Absence or failure of mandatory navigational systems and equipment
• Absence or failure of radio communications systems
• Number, composition or certification of the crew not corresponding to safe manning certificates

Under load lines

• Insufficient stability or ability to calculate stability conditions
• Significant areas of damage/corrosion/pitting of deck and hull affecting seaworthiness
• Absence of poor condition of hull closing devices such as hatch covers and watertight doors

Under MARPOL

• Absence or poor condition or failure of OWS, ODMCS, and alarms
• Remaining capacity of slop tanks/sludge tanks insufficient of the intended voyage
• No oil record book

Under STCW

• Lack of or insufficient crew member certificates/endorsements
• Inadequate navigational / engineering watch arrangements/personnel
• Competency of crew members not adequate for the duties assigned for the safety and security of the ship and prevention of pollution
• Insufficient rested watchkeepers for the first and relieving watch duties at the commencement of the voyage

Under ILO convention

• Insufficient food and portable water for the next voyage
• Excessively unsanitary conditions on board
• No heating in accommodations if ship operated in low temperatures
• Excessive garbage blocked passageways

Once the detention order has been placed on a ship, it is likely to remain part of the historical port state records for that ship and be displayed on the web for at least 3 years. A detentions order might include an instruction that the ship has to remain in a particular place or move to an anchorage or other berths. The order should specify the circumstances that would allow the detention to be released The fact that a ship had been detained should be clearly stated on "Report form".