Theory time.
a.) Captain was coerced against his will into blocking the canal by derps and was trying to send a message that the derps wouldn't catch, but that someone later would.
b.) Captain knew there was illicit cargo (human, drugs, weapons, NUKES) and sent the message on his own recognizance (I know, wrong word, but I like it) and then stranded the ship to put an end to the evilness all on his lonesome.
And blocked Suez canals get attention.
I can see no reason, other than blowing up the canal, for him to purposefully block the canal of Nukes were onboard and he knew it.
So, yea. I'm gonna hang out in the ballpark of these theories until proven otherwise.
\Of course, if its nukes, we may never know.
Given the direction of the final destination, I’d say that he, ummmm, f’ed up....