what is the meaning Berth in maritime law and international law

Place in a port alongside a quay where a ship loads (loading berth) or discharges
(discharging berth) cargo or, in the case of a lay- by berth, waits
until a loading or discharging berth is available. This term is also frequently
used to signify a place alongside a quay, each of which is capable of accommodating
only one ship at a time.
When a ship arrives at a port, the requirement for her to be on the berth
or not is important in determining the commencement of laytime, that is,
the time allowed for loading or discharging, as the case may be. In the case of
a berth charter- party, a particular berth is nominated by the voyage charterer;
notice of readiness to load or discharge, as the case may be, can only be
given by the charterers when the ship reaches the berth. Conversely, a port
charter- party stipulates that, once the ship has arrived at the port, laytime
will start to count whether or not the ship has reached a berth. There may be
other factors affecting the commencement of laytime, notably the requirement
in certain cases to tender notice of readiness; these will be provided for
in the charter- party.
A safe berth is one at which it is physically safe for a vessel to remain. A
frequent clause in voyage charter- parties places the responsibility onto cargo
interests to order the chartered ship only to a safe berth, for the purpose of
loading or discharging. This is expressed as one safe berth when it is further
intended to restrict cargo interests to one berth only.
To stem a berth is to reserve a berth for a ship. This is routinely done at
the port by the ship’s agent with the appropriate terminal operator prior to the
ship’s arrival.
A common berth or common user berth is one whose use is not restricted
to the ships of any one line or shipping company.
Berth dues are charges made by a port authority for the use of a berth
to load or discharge cargo. The charge may be based on the ship’s register
tonnage, the number of days on the berth and the amount of the cargo. Also
known as berthing dues or berthage and often used synonymously with
quay dues, wharf dues and wharfage