政府根據《憲法》第二百條第一款c項之規定，命令制定法規如下：
獨一條—— 通過一九八七年十一月在倫敦訂立之《1972年國際海上避碰規則公約修正案》，以待加入；該修正案之英文原文及葡文譯本附於本命令。
一九九零年八月三十日於部長會議批閱及通過—— Joaquim Fernando Nogueira —— Joaquim Fernando Nogueira —— Álvaro José Brilhante Laborinho Lúcio —— João de Deus Rogado Salvador Pinheiro —— Álvaro Severiano da Silva Magalhães —— Fernando Nunes Ferreira Real.
一九九零年九月二十八日批准。
命令公布。
共和國總統
Mário Soares
一九九零年十月三日副署。
總理
Aníbal António Cavaco Silva
（一九九零年十月二十日第243期 《共和國公報》 第一組）
1 — Rule 1 (e) — Vessel of special construction:
The existing text is replaced by the following:
(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 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.
2 — Rule 3 (h) — Vessel constrained by her draught:
The existing text is replaced by the following:
(h) The term «vessel constrained by her draught» means a power-driven vessel which, because of her draught in relation to the available depth and width of navigable water, is severely restricted in her ability to deviate from the course she is following.
3 — New rule 8 (f) — Not to impede:
The following new paragraph (f) is added:
(f) (i) A vessel which, by any of these rules, is required not to impede the passage or safe passage of another vessel shall, when required by the circumstances of the case, take early action to allow sufficient sea room for the safe passage of the other vessel.
(ii) A vessel required not to impede the passage or safe passage of another vessel is not relieved of this obligation if approaching the other vessel so as to involve risk of collision and shall, when taking action, have full regard to the action which may be required by the rules of this part.
(iii) A vessel the passage of which is not to be impeded remains fully obliged to comply with the rules of this part when the two vessels are approaching one another so as to involve risk of collision.
4 — Rule 10 (a) — Traffic separation schemes adopted by the Organization:
The existing text is replaced by the following:
(a) This rule applies to traffic separation schemes adopted by the Organization and does not relieve any vessel of her obligation under any other rule.
5 — Rule 10 (c) — Crossing traffic lanes:
The existing text is replaced by the following:
(c) A vessel shall, so far as practicable, avoid crossing traffic lanes but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow.
6 — Annex I, section 2 (d) — Uppermost light:
The existing text is replaced by the following:
(d) A power-driven vessel of less than 12 metres in length may carry the uppermost light at a height of less than 2.5 metres above the gunwale. When however a masthead light is carried in addition to sidelights and a sternlight or the all-round light prescribed in rule 23 (c) (i) is carried in addition to sidelights, then such masthead light or all-round light shall be carried at least 1 metre higher than the sidelights.
7 — Annex I, section 2 (i) (ii) — Vertical spacing of lights:
The existing text is replaced by the following:
(ii) On a vessel of less than 20 metres in length such lights shall be spaced not less than 1 metre apart and the lowest of these lights shall, except where a towing light is required, be placed at a height of not less than 2 metres above the gunwale.
8 — Annex I, section 10 — Sailing vessels lights:
In section 10 (a):
In the lead-in, the word «underway» is added after «sailing vessels».
In section 10 (b):
In the lead-in, the word «underway» is added after «sailing vessels».
9 — Annex IV, new paragraph 1 (o) — Distress signals:
The following new paragraph (o) is added:
(o) Approved signals transmitted by radiocommunication systems.