When choosing the proper reel for big game fishing there are very considerations to take into account.
The most important decision will be the size of spool you decide to go with. If you are going to be chasing down big marlin, swordfish, and tuna, then you are going to need the line capacity for their strong runs.
A reel such as a Shimano 80 or Shimano 130 is sufficient to withstand the big runs of strong black marlin and big swordfish. When the fish is dumping line with considerable heat, it is important to try not to button down the drag too tight, as a reel losing line gets increased drag on its own.
You will also want to consider going for a 2 speed reel. When a fish charges the boat, reeling in on the second speed has great advantages to catch up and get rid of the belly in the line.
We strongly recommend you get yourself a quality lever drag reel if you are going to be going after the big fish. It is much easier to work for inexperienced anglers and very smooth.