RE: bigger fin on carve 144l 07
I'm glad to see that you've gotten some solid input from Phill and Ian, especially since they're offering first hand experience with Carve 144.
In light of your second post above, I thought I would add a few more comments. It's great that you haven't let your age be a limiting factor in your activities. I'm in my late 50s, and I can assure you that windsurfing is a spirited sport that you can pursue and still excel at far beyond the limits of youth. Windsurfing is kind of like snow skiing, where the development of basic skills can allow you to experience the excitement and challenge of physical fun late in life.
Regarding your learning curve, Phill identified a very important point. Working on your technique will allow you to reap the greatest rewards. Combine this with a bit of friendly competition, and its surprising how it will combine to enhance your improvement curve. Also, I think that if you hang tough on the 8.5 for your light wind sailing, you will find that it tightens up your timing and skills tremendously. This will show itself readily when you drop down the 7.2 in stronger conditions.
Lastly, I have found that many folks tend to balk a bit about bringing all of their equipment to the beach. I don't know how many times I've heard the comment that their day would have been better if they brought this or that to the beach. I know that limits are sometimes a reality, but from my point of view, it's critical to always bring your light wind stuff. More often than not, light winds are our fate, and its best to be prepared.