COLREGs Rule 1 Application

Paragraph A :

This rule shall apply to upon high seas and in all waters connected therewith navigable by seagoing vessels

Explanation: 

All vessels - This means the can be big or small. It can be fishing vessel , yachts , barges and all other kinds and categories of vessels.
High seas - This include all the major oceans and seas.
All connected waters - This include all the rivers and gulfs that have ports on their banks and are accessible by sea going vessels.

Paragraph B :

Nothing in these rule shall interfere with the operation of special rule made by an appropriate authority for roadsteads , harbours , rivers , lake or inland waterways connected with highseas and navigable by seagoing vessels. Such special rule shall conform as closely as possible to the rules.

Explanation:

Harbor or port authority of a country make their own rules of port entry , exit and anchorage . But these rules shall not have a negative impact with the colreg rule. Colreg rules will be followed as usual within the area as it is outside. In addition to that special rules of that harbor or port will be followed very similar to colreg to avoid confusion and accidents. But these rules shall remain restricted within a confined area like harbour, rivers, lake, or inland waterways as stated above.

Paragraph C :

Nothing in these rule shall interfere with the operation of special rule made by the government of any state with respect to additional stations or signal lights, shapes or whistle signal for ships of war and vessels proceeding under convey, or with respect to additional stations, signal lights or shapes for fishing vessels engaged in fishing as a fleet. These additional stations or signal lights, shapes or whistle signal shall so far as possible be such that they cannot be mistaken for any light, shapes or signal authorized elsewhere under these rules.

Explanation:

If a government of a country has made any compulsory special rule for ships and fishing vessels to show certain additional stations, lights, shapes or whistle signal . Then they should not be confusing with the other lights, shapes or whistle signal given in colregs . 

This paragraph do not say whistle signal for fishing vessels engaged in fishing as a fleet. And also these additional rule cannot be applied for single or independent fishing vessel that is not a part of the fleet.

Paragraph D :

Traffic separation scheme may be adopted by the organization for the purpose of these rules.

Explanation:

Organization - IMO

So in that sense IMO may implement a traffic separation scheme at any place for the betterment of the traffic control. This traffic separation scheme is adopted to enhance the effectiveness of these rules.

Paragraph E :

Whenever the government concerned shall have determined that a vessel of special construction or purpose cannot comply fully with the provisions of any of these rules with respect to number, position, range , arc of visibility of lights or shapes as well as to the disposition and characteristics of sound signaling appliances ,such vessel shall comply with such other provisions with respect to number , position , range or arc of visibility of lights or shapes as well as to the disposition and characteristics of sound signaling appliances, as her government shall have determined to be the closest possible compliance with these rules in respect of that vessel.

Explanation:

If a specially constructed ship (aircraft carrier , research vessels), which due to the nature of the special fitted does not have places to fit the lights or shapes as required by the collision regulation annex 1 (position and technical details of lights and shapes ), then the government may allow these special ships to carry their lights or shapes in a different place (it can be at the sides or at the extreme forward or aft) , but it shall make sure that these lights or shaped are the closest deviation from the colregs and they are almost similar to those fitted on regular ships