I believe that's the limit of choices until the Boxer arrives.
Once the Boxer is within a couple of hundred miles, every conceivable option is on the table. They have every possible tactical system aboard.
Thes Pirates are not Jihadists or ideological fanatics. They are simple gangsters trying to extort money. If I were talking with them, I would put things in simple terms. If you kill the Captain, we will kill you. In the meantime, you just sit and wait. Keep them on the high seas. Jam any communication they have with their allies. While you are doing this, you start tossing up flares at night and playing a lot of loud music. Keep inching your large vessels closer and closer. Send you aircraft including helicopters on constatnt close reconnaisance. Eventually, they will crack.