In my mind, there are two separate issues for low level PvP:
Low level players fighting other low level players.
Low level players being competitive against high level players.
The first is something that we have minimal support for right now. It certainly can happen, if you chance upon another low level player in a PvP zone, but it's honestly not that likely. We have a cunning plan* to address this with the skirmish system. Basically we plan to allow players to create skirmish battles that are limited by level, or by ship size, or both. Unfortunately that system will take some time to get to you.
The second issue, low level players being competitive against high level players, is a bit trickier. One of the things I'm happiest about in Pirates is that a low level player at least has a chance against the higher level player. A cannon ball is a cannon ball, and a low level player in a small fast ship can, potentially, outmaneuver and out play an opponent in a powerful high level ship. I still feel that is the case, however there are some caveats.
First, no matter how good you are, a small ship is unlikely to be able to take on multiple high level ships. The advantage of the small ship is maneuverability, his strategy is to avoid the big guns of his opponent. When there are two sets of big guns bearing down on you, avoiding them becomes exponentially more difficult. Ultimately we don't ever expect a single small ship to be able to take on more than one high level ship successfully. I now encourage all small ship captains to prove me wrong.
Secondly, we want level to be an advantage. High level ships should be big and powerful. Taking them on in a lower level, small ship should be a significant challenge. If you manage to win that fight it should be a major accomplishment, something you can brag about on the message boards.
On top of all that, there are some high level ships that are specifically designed to counter small fast ships. This was one of the real life rolls for frigates: chasing down the small harassing ships of pirates and privateers. There are some match ups that simply do not favor the small ship.
Finally, on the topic of more PvP zones: Yes we need more. Yes, it will likely be beneficial to low level players interested in PvP if there are more PvP zones. We're working on ways to make that happen.
*used with permission of Baldric's Turnips LLC.