What is meaning of Unsafe ship/when a ship is called unsafe?

In the M.S. Act 1958 of India as amended the meaning of unsafe ship is as  follows:-

Under section 336, unsafe ship may be defined an unsafe ship, that is to say, is by reason of the defective condition of her hull, equipment or machinery, or by reason of overloading or improper loading, unfit to proceed to sea without serious danger to human life, having regard to the nature of service for which she is intended.

1. A ship is said to be unsafe, when the hull and equipment is temporarily defective and the ship is unsafe for that proposed voyage.
2. A ship is said to be unsafe when its master, officers and crew are qualified but do not follow the safe working  practices.
3. Not maintaining the required provisions laid down in certificates can make the ship unsafe  during the voyage.
4. A ship is said to be unsafe if the machinery or equipment is placed on board but found not working or   the maintenance plan is not being followed.
5. An unsafe ship does not pose serious threat to human life.
6. A ship is said to be unsafe when its machinery or equipment is operated wrongly at any   instance by the ship’s crew in the voyage.
7. Wrong procedure of ballasting, deballasting or negligence of crew towards stowage of cargo makes the ship   unsafe an any instance during voyage.

In broad perspective or loosely we can say ship become unsafe due  human error.