RE: bigger fin on carve 144l 07
Given no response to date from the Starboard Team, I thought I might offer a quick thought or two. While I have to frank about lack of any actual experience with the Carve 144, I noted that the 2007 model is spec'ed around fin sizes in the 42-54cm range. The general rule of thumb indicates that smaller fins work best with smaller sails, and conversely larger fins work best with larger sails. Now, there is quite a bit flexibility possible to satisfy personal preferences, so really, one needs to experiment a bit. Sometimes it's best to borrow different fins from friends to learn more about what can be gained or lost through use of different sizes. Buying new high quality fins can be quite expensive, so its best to test a bit before making the investment. Really, it doesn't hurt to ask your local retailer if they have a demo policy. You might be pleasantly surprised.
In your current scenario, I would say that a 54 cm fin would work better with the 8.5 than the 7.2. Although some folks may view a 54 to be on the large size for the 8.5, in the lower wind ranges you will probably find it helps greatly with early planing. With respect to the 7.2 in lighter winds, I would expect the optimum fin size would most likely range between 46-48cm.
Again, I would highly recommend testing different sized fins to see what you like best.