First, here is a pretty good summary of what has taken place (including videos) posted by RT:
I will just add that at the time of writing (07:38 UTC) the cargo ship blocking the passage under the bridge has been removed, traffic has resumed and the situation has returned to normal.
Second, let me give you the single most important element to understand what is (and what is not) taking place: the Sea of Azov and the Black Sea are, in military terms, “Russian lakes”.  That means that Russia has the means to destroy any and all ships (or aircraft) over these two seas: on the Black Sea the life expectancy of any intruder would be measured in minutes, on the Sea of Azov in seconds.  Let me repeat here that any and all ships deployed in the Black Sea and the Sea of Azov are detected and tracked by Russia and they can all easily be destroyed.  The Russians know that, the Ukrainians know that and, of course, the Empire knows that.  Again, keep that in mind when trying to make sense of what happened.
Third, whether the waters in which the incident happened belong to Russia or not is entirely irrelevant.  Everybody knows that Russia considers these waters are belonging to her and those disagreeing with this have plenty of options to express their disagreement and challenge the legality of the Russian position.  Trying to break through waters Russia considers her own with several armed military vessels is simply irresponsible and, frankly, plain stupid (especially considering point #2 above).  That is simply not how civilized nations behave (and there are plenty of contested waters on our planet).
Fourth, one should not be too quick in dismissing Poroshenko’s latest plan to introduce martial law for the next 60 days.  Albeit Poroshenko himself declared that this mobilization does not mean that the Ukronazi regime wants war with Russia, the fact is that the first-line reserves will be mobilized.  This is important because the situation resulting from the introduction to martial law could be used to covertly increase the number of soldiers available for an attack on Novorussia or, God forbid, Russia herself.  In fact, Poroshenko also officially appealed to the veterans of the war against Novorussia to be ready for deployment.
Fifth, while there are all sorts of caveats offered by the Ukronazi regime about the introduction of the martial law, including that it will not mean war or infringe on the right of the people, the truth is very different.  Here is what a memo by the Unian agency says about what martial law means in legal terms: (emphasis added)
Martial law is a special legal regime that is introduced in Ukraine or its individual areas in the event of armed aggression or threat of attack, a threat to Ukraine’s state independence, its territorial integrity, and gives authorities, the military command and local self-government the powers that are necessary to prevent threats and ensure national security. It also foresees temporary threat-related limitations on constitutional rights and freedoms of a person and a citizen and the rights and legal interests of legal entities, indicating the duration of such restrictions (Article 1 of the Law on the Legal Regime of Martial Law).
Considering the current single-digit popularity rating of Poroshenko and the fact that he has no chance in hell to be re-elected (at least not in minimally credible elections) it is pretty darn obvious of why the Ukronazi regime in Kiev decided to trigger yet another crisis and then blame Russia for it.  The very last thing Russia needs is yet another crisis, especially not before a possible Putin-Trump meeting at the G20 Buenos Aires summit later this month.  In fact, Ukrainian bloggers immediately saw this latest provocation as an attempt to scrap upcoming elections.
So what’s next?
Well, the most likely options is just one more Ukie bawling about the “Russian aggression” with the hope that this will a) raise the value of the Poroshenko regime in the eyes of the Empire and b) disrupt the planned Trump-Putin meeting.
I am not so sure that Poroshenko will be given the option to simply cancel the elections.  Yes, he cannot win, but the Empire can replace him.  Not only that, but outright canceling the elections would be a PR disaster (but one which is sometimes chosen by the Empire’s “sons of bitches” like, say, Mahmoud Abbas).  Still there is also a very good chance that the Ukronazis regime feeling that it has nothing to lose would take such an unprecedented step.
Some kind of limited Ukronazi military operations against Russia, Novorussia, Crimea or the Kerch bridge would be militarily suicidal but political very profitable as it would allow Poroshenko to a) blame Russia for all the Ukrainian problems and b) demand even more aid to “resist against the Russian aggression”.  The problem with that option is that there are good signs that a lot of the Ukrainian military personnel does not have the courage to actually fight the Russians (for ex: look how ALL the Ukie soldiers folded in Crimea; also, the blog of “Colonel Cassad” reports that of the three ships which tried to breach the Russian border, at least one had a captain who voluntarily surrendered his ship to the Russians; finally, one Ukrainian sailor has apparently been shot for refusing to open fire against the Russians).  It is worth mentioning that on Sunday the Urkonazis sent a few more ships obviously to aid the ships intercepted by the Russians, but as soon as the Russians closed the passage and Russian Su-25s and Ka-52 appeared in the skies, they quickly stopped and eventually left the scene.  Did they do that under order or because they did not want to die?  We will never find out I suppose.
Finally, there is the very real possibility of a full-scale war against Russia.  Yes, the Ukronazis would last just a couple of days, but keep in mind that their goal will not be to win, but to force Russia into an overt military operation which the entire “collective West” will have to condemn like what happened with the Georgian attack in 08.08.08. (you know, in the name of “solidarity” like during the Skripal false flag).  As for the leaders of the Anglo-Zionist Empire, they will gladly fight Russia down to the very last Ukrainian solider, we all understand that.
Finally, let me address those who might think that Russia somehow over-reacted or should not have used force.  First, let me remind you that we are talking about armed and militaryvessels, not fishing boats.  Second, the Ukronazis have been daydreaming about bringing this bridge down even before it was built.  So how where the Russians to know that these ships were not packed with explosives?  Third, let me remind you that a few months ago the Ukronazis did send a few tiny military vessels under the bridge.  That first time, they did ask for permission and even had a Russian pilot on board helping them to cross the narrow passage.  Yet the regime in Kiev presented that a major “victory” against the Moskal’s.  This time around tried to sneak by without asking.  If the Russians had left them pass, what do you think they would have done the next time?
The truth is that the Ukronazi regime has been claiming for years now that it is at war against Russia, that Russia has invaded the Ukraine, that all those who oppose the regime or speak even the basic truth are “agents of the Kremlin/FSB.  The funny thing is not just that this is the first time in Russian history that Russia is accused of waging a war which shes does not even participate in – it is even more hilarious that the Ukronazis claim to be at war with Russia but have a hissy fit when three of their (tiny) ships are arrested for violating the Russian border.  Is there a war going on or not?!  What the hell were they thinking when they tried to force their way through?!
[Sidebar: there is even a joke about this going around: Ukrainian military personnel are asked why they are fighting in the Donbass.  They reply “because the Russians are there”.  Then they are asked why they are *not* fighting in Crimea and they reply “because the Russians are truly there!!”.  Bottom line: everybody knows full well that this is bull and that there are no Russian forces in Novorussia]
How do you prove that the other guy is an “aggressor state”?  Simple – by forcing him to attack you.  Considering the “selective blindness” of the collective West, the fact that you hit the other guy first makes absolutely no difference whatsoever (again, see 08.08.08).
It is obvious that the Nazi regime in Kiev is in a tailspin and that short of some dramatic action Poroshenko is a goner.  Most of the gang around him won’t fare much better, especially not if Timoshenko ever gets the presidency (which might happen if the Empire decides to ditch Poroshenko).  For them the options are either to leave the Ukraine or face some serious jail time (sort of the same situation as Saakashvili had to face).
We are entering a very dangerous time period, one in which a totally corrupt Nazi regime will fight with every trick imaginable to save itself.  Whether this will result in a major war against Novorussia or Russia is impossible to predict, but we have to recognize that this is a distinct possibility.
The Saker
UPDATE: Monday November 26th 11:11UTC:
Looks like Poroshenko ran into some real problems in the Rada.  Unsurprisingly, pretty much all the political parties have immediately understood what this was all about and have categorically rejected the text Poroshenko submitted.  They only adopted a much watered-down version in which the martial law is introduced only for one month, not two, and the fact that the elections will take place as scheduled has been re-confirmed.  Thus our “favorite” Uber-loser Poroshenko again failed in his latest plan and we must expect more crazy stuff as this regime will not go down gracefully.  Stay tuned!