I have a Broadcast 5.6, weigh about 220, but have the older Lightning hull. I have no trouble surfing the Broadcast.
You don't need that much ballast to start wakesurfing, but you need all of what youíve got on the surf side of the boat. The, center tank only might not be enough, make sure that all of your people ballast is on the surf side of the boat too. You have a better surfing hull than I have, you should make a pretty good surfing wake. The starboard-goofy side wake wonít be as good as the port-regular side. It takes a lot to make a good surfing wake on my boat. If youíre goofy it will be more difficult.
I need at least 14 feet lake depth to make a wake, how deep is your lake?
We always start first timers out a little slower. If youíre loosing the boat then just slow the boat down. I surf any where from 8.5 mph to almost 15 mhp. Like above donít get in a hurry to drop the rope, and weight forward is also a good tip. The rope should go slack when you find the pocket.
The tribal wake surfing knowledge says that once you learn how to surf and really get the hang of it you can surf faster and you can surf smaller boards. At my weight I can surf the smallest Trick Boardz velocity at 8.5 mph. That small Velocity is like surfing a postage stamp. If I can surf that little thing you can surf a Broadcast 5.6
I run a little over 2,000 pounds of ballast in the Mighty Centurion. The older hull needs a lot of list (lean to one side) to make a good surfing wake. I put all 2,000 pounds of ballast and crew on the surf side of the boat.
The wakesurf forum is pretty active and there are lots of helpful folks, you might want to post other wakesurf questions there.
Here area couple of wake pics