Hi Roberto
That's terrible luck that you are stuck there for another month!
I don't actually know what's going to be available, but i would suspect that you will have a number of Tuna species and possible the odd shark or spearfish that may take a lure.
For the best all round chance of a take I would run a couple of decent Rapalas about 80 yards behind the boat. Nothing flash, keep it simple and that should find Tuna. For something a bit more exciting, look at some of the surface lures that would be used worldwide for Marlin and Billfish. Don't go too big, keep them to under 12" in the first instance.
Finally, at night, try fishing squid style lures, trolled very deep with a glowstick attached.... you may just weedle out a Broadbill Swordfish.
It can be done by the sailing boats, look closely at the picture....