With the US captain in that enclosed life raft and hijackers sitting next to him?? If the Seals attacked he would be dead in a second.
Get the captain out first with a ransom them bomb them into submission. Kill them all.
I would certainly hope you give our professional special forces a little credit for being better than a few thugs - even if they are packing heat. As others have pointed out (and with respect to post #67 in particular): if we were allowed to act, this would be over.... quickly. And then nobody would screw with the United States.
Now is there some risk? Yeah, there is -- but the captain has already shown himself willing to accept some risk: first by allowing himself to be the fall guy to protect his crew, and then by trying to escape without any support.
The problem is the containment of the lifeboat. Taking that away without getting the Captain killed is the main problem. So why not use the ocean as an ally? Slowly, by blasting holes that then fill the boat with water and force them out (even if it doesn't sink). Or fast, by slicing a whole end off of the boat by wrapping it with det cord or something similiar. Once they're in the drink, the SEALs own them.