A quick analysis of the astro charts for the Suez Canal obstructions and closures (and associated efforts to clear up the obstacles). [Will add charts and links to Wikipedia for more info later on.]

Suez Canal Obstruction in 2021

At the time of the 6-day event (Mar 23-29, 2021), Mars was conjunct the North Node in Gemini, while Mercury in Pisces squared both Nodes (and Mars). The Nodes were in 11-12 degrees of Gem/Sag (focus on international travel/commerce). In essence, there was  a t-square involving Moon Nodes in Gem/Sag, Mars, and Mercury. This was a stressful combination indicative of problems with international travel/trade and maritime navigation.

Suez Canal closure in 1956 after a British-French-Israeli invasion

Back in October 1956, during the Suez Crisis, the canal was similarly closed when Saturn (blockage) conjoined the North Node in Sagittarius. 

Suez Canal 8-year closure in 1967 to 1975 after the Arab–Israeli Six-Day War

Suez canal has also been closed for 8 years from 1967 to 1975. Following the Yom Kippur War between Egypt and Israel in 1973, an international agreement was reached to provide measures to reopen the Suez Canal after its closure during the 1967 Six-Day War. The Suez Canal Clearance Operation was completed on Dec 19, 1974 just as Neptune and Mars conjoined the South Node at 10 degrees of Sagittarius, while being squared by Jupiter in 11 degree of Pisces. [Jupiter rules Sagittarius and is associated with international travel; Pisces is a water sign associated with maritime travel]. So at that time, there again was a t-square at virtually the same degrees of Gemini, Sagittarius, and Pisces as during the 2021 event. Both times, Mars conjuncted a Moon Node (accidents, fighting, dangerous or intense activities that affect large groups of people). And both times, the activities involved major efforts to clear the canal from obstructions.

Suez Canal Short-term Obstructions in 2004, 2006, 2017, and 2018

Back in November 2004, there was another three-day canal closure after a Russian oil tanker ran aground. Tense transits at the time were Mars square Saturn (Libra to Cancer) = stress, breakdowns, loss of balance; and Mercury square Uranus (Sagittarius to Pisces; 2-3rd degrees) = sudden problems with maritime travel, miscommunication, accidents, sudden power loss, windy conditions. 

On February 10 2006, a Hong Kong-flagged Okal King Dor cargo ship blocked the Suez Canal for 8 hours. At that time, Mercury and Uranus were widely conjunct in Pisces (Mercury was at the same 2 degrees as Uranus was in 2004 when the Russian oil tanker ran aground).

Finally, on Jun 6 2018, a Mega container ship OOCL JAPAN suffered steering failure in Suez Canal. [Mars precisely conjunct South Node in Aquarius; Mercury-Sun tightly conjunct in Gemini in exact square to a tight Neptune-Moon conjunction in Pisces). The  same ship previously ran aground in the canal on Oct 18 2017. [Mercury tightly conjunct Jupiter in Scorpio; Sun in Libra in opposition to Uranus in Aries; Virgo Mars in a wide square to Saturn in Sagittarius.] Both times, the ship was freed within a few hours.

Summary

In all, it looks like Suez canal obstructions and clean up efforts often involve conjunctions of Mars to Moon Nodes (aka Rahu and Ketu) as well as difficult transits of Mercury to Neptune, Uranus, or Mars (especially in Gemini, Sagittarius, and Pisces).