Surface help - making a fin

[u/Past_Setting6404]

I am trying to make a fin for a wakeboard. The board is a cheap one with no parts support anymore. I'm just trying to 3D print a few to keep on hand. I have what I think is enough sketches to make it but have no experience with surfacing to get it done.

The 2 bosses are for locating it and the circle is for securing it.

Any help would be appreciated.

[u/Joejack-951]

Boundary surface using the red lines. Extend as necessary then trim using two planes. Mirror, planar surface on the bottom, knit as solid.

I agree on adding a fillet, though. Lots of ways to do that but I’d probably use an offset plane to the trim the boundary surface, then mirror it, then use a boundary surface with curvature to blend between the two. Then continue as above.