Rule 1 Explained

Application
(a) These Rules shall apply to all vessels upon the high seas and in all waters connected therewith navigable by seagoing vessels.
(b) Nothing in these Rules shall interfere with the operation of special rules made by an appropriate authority for roadsteads, harbours, rivers, lakes or inland waterways connected with the high seas and navigable by seagoing vessels. Such special rules shall conform as closely as possible to these Rules.
(c) Nothing in these Rules shall interfere with the operation of any special rules made by the
Government of any State with respect to additional station or signal lights, shapes or whistle
signals for ships of war and vessels proceeding under convoy, or with respect to additional station or signal lights or shapes for fishing vessels engaged in fishing as a fleet. These additional station or signal lights, shapes or whistle signals shall, so far as possible, be such that they cannot be mistaken for any light, shape or signal authorized elsewhere under these Rules.
(d) Traffic separation schemes may be adopted by the Organization for the purpose of these Rules.
(e) Whenever the Government concerned shall have determined that a vessel of any special
construction or purpose cannot comply with the provisions of any of these Rules with respect to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signalling appliances, such vessel shall comply with such other
provisions in regard to the number, position, range or arc of visibility of lights or shapes, as well
as to the disposition and characteristics of sound-signalling appliances, as her Government shall
have determined to be the closest possible compliance with these Rules in respect of that vessel.

Explanation

Rule 1 (a)
Rules shall apply to:
* all vessels
* upon the high seas
* in all waters connected therewith
* and
* navigable by seagoing vessels

Rule 1 (b)
Special Rules are :
Local Rules that apply to :
* Roadsteads
* Harbours
* Rivers
* Lakes or Inland waterways
These special Rules must conform as closely as possible with the 1972 Regulations
Rule 1 (b)
Mariners can find Local regulations in:
* Sailing directions
* Pilot books
* Guide to Port Entry

Rule 1 (c)
For what type of ships can a Government issue special rules ?
* Ships of war
* Vessels under convoy
* Fishing vessels fishing as a fleet
* Dracones
* Submarines
* Aircraft-carriers

Rule 1 (d)
* Traffic separation schemes (TSS) may be adopted by the Organisation

Rule 1 (e)
* Exceptions in the Rules may be made for vessels of special construction

Questions and Answers
Q1 If you were in charge of motor launch approaching the Port of Dublin and you meet a large ferry, do the IRPCS apply?

Answer
Yes they do apply as you in a vessels on high seas and in navigable waters connected to the high seas.

Q2 Can Governments make modifications to the COLREGS in relation to additional station or signal lights, shapes or whistle signals for ships of war and vessels proceeding under convoy and station or signal lights or shapes for fishing vessels engaged in fishing as a fleet?

Answer
Yes Governments are allowed to make modifications to additional station or signal lights, shapes or whistle signals for ships of war and vessels proceeding under convoy and station or signal lights or shapes for fishing vessels engaged in fishing as a fleet