>> The Frigate and Destroyer can land a small helicopter, but it would take several trips to get a SEAL team and their supporting, specialized equipment aboard.
So make several trips.
I’m fairly certain you could not hoist and land a mini-sub on either, much less launch it.
So don’t send one. I think a mini-sub is of questionable utility in this case.
>> Too simply drop SEALS with small arms in the water near the lifeboat will do little besides get them shot.
So drop seals with rebreathers (no bubbles) — lots and lots and lots of them, in multiple waves. Let the freaking jihadis see them coming! For starters, just let them swim toward (but underneath) the boat, reconnoiter, and swim away. Let the monkeys get nervous. Real nervous, wondering what’s next. Have you seen that boat? I used to build ‘em. Note, they have only a few doors and windows. you either stay outside on the flange or very top — vulnerable — or open the doors — again, vulnerable. At the right moment, create a distraction to let a seal or two board. Or bang-stick a hole in the thing and pump in sleeping gas or tear gas. Or SOMETHING.
My point is, to say that a) there’s no way to get seals in there RIGHT NOW, and b) even if seals were there there’s nothing they could do, is not only defeatist, it’s technically wrong.
Until then I suspect they are trying to maximize the chances of retrieving that captain alive.
Any other thing that badly scares the pirates could result in them killing the captain. Shooting one pirate would cause the the other pirates to shoot the captain. That omits anything a Seal team could to the boat - other than quietly adding a tow rope .
So, scratch any hull entry from below, or boarding.
Even a tow line is problematic though. If a rope is attached, the pirates could easily drop over the side, and cut it... unless it's a small steel line. What Seals attach, pirates could easily detach.
There is only one thing that might save that captain - the arrival of 2 mil in cash, which ~might~ result in an exchange.