Here is one fin closed. You can do the same for the ends also.. If you split the edge into 2 by trimming, you can use the blend tool to get a nice end shape...

Hi Gary, the method Burr shows is a good way to do it.

Just to clarify, that method involves using the Trim command to cut the ending edge so that it is in 2 pieces, and then you can use the Blend command to blend between those 2 pieces.

When you are in the Trim command when it asks you for cutting objects you click the "Add trim points" button to tell it you want to pick a point to cut at instead of selecting a cutting object.

Also before selecting the edge, hide any of the original construction curves that you may have right on top of it, otherwise it is difficult to select the surface edge because the curve will be in the way of it.

- Michael

Wow, that's really nifty. You just have to be careful where you put the trim points or you may get more than 2 segments which don't work.

I ended up using a sweep with a big end and a scaled down small end with a long arch to create the wing / fin.

This is so simple when you know what you're doing.

Thanks BurrMan and Michael!

Gary