how can I improve my speed?

Question
I'm on the swim team and I just started last year at my highschool but I can only swim during swim season which lasts for about 2 months and then I'm pretty inactive, I wanted to practice during the time that I'm off the team but I don't have a pool and my parents won't allow for me to join a club swimming team. I really want to get better at swimming and I really want to become an integral part of the team because right now i swim a 50 in 40 seconds and thats just so slow. I can't swim fast but when my coach makes me swim 200's and 500's I can set a good pace that I can keep consistent but I would really like to know if there is anything I can do now, while I am still in swim season, and later, after swim season ends and I no longer have access to a pool, to help improve my speed.

Answer
Tiffany,
You pose a great question.  The best thing to do for swimming is to swim.  However, maintaining your cardiovascular strength is integral for swimming.  I would say that number one thing you can do in the off season is keep up your cardio.

You can do this by running, biking, taking aerobics classes, etc.  I really think that you need to just maintain your activity.  Also, you will want to concentrate on your core.  Your core is mainly your abs.  Keep these up and and you will do fine.

If you can get into a pool at all, that would be great.  If not.  You just need to make sure you stay active and keep your cardio up.

Best of luck.
Eric