Match up a sky triangle with a sail triangle as shown

Flip the sky over the sail as shown so that right sides are together. Although not shown in this picture, I cut a matching triangle of paper to keep the bias seam from stretching as I sewed.

Draw a mark 1/4 inch from the edge at either end of the sky triangle piece to help you align the two pieces. The mark should be at the straight edge of the triangle underneath.

Stitch the two triangles together, remove the paper from the back and press the seam toward the sail (or the darker fabric).

Trim carefully to 3.5 x 9.5

Repeat these steps for three sail elements. You will have one set left over.

Cut a sky block 3.5 x 9.5 and sew the three sail elements and the sky block together forming the upper portion of the block.

Cut a 4" block of the dark blue water and the boat fabric. Draw a line on the diagonal and put the two blocks right sides together.

Cut a rectangle of the boat fabric that is 6.5 x 3.5 and set aside.

Sew the two four inch blocks together a scant 1/4 inch from both sides of the diagonal line.

Cut on the diagonal line and press toward the darker fabric.

This will give you two half square triangles for the bow and stern of the boat.

Sew the bow to rectangle and stern to the other end of the rectangle using a scant 1/4 inch seam.

Press. You should now have the 'boat' portion of the block that measures 12.5 x 3.5

Sew the sail portion to the boat portion using a scant 1/4 inch seam. Press. Square block to 12.5 x 12.5.

All you need now is some wind!