Using a wireless internet connection will be more laggy, due to you not being directly connected (or something like that
).
Other than that, all I can suggest is lowering your graphics.. not really sure. As MacIronhawk said, majority of the lag is on their end. I play with my graphics on high (and have done so since I first joined). I used to be able to play the game lag-free. However, once they updated the islands, my lag increased. The only reason I think it's on their end is exactly as MacIronhawk mentioned, I've played better looking games lag-free, on the same computer. Once I sign on to Pirates, it's a completely different story.