This pattern was well written and easy to follow, and quick to make. Very helpful chart to determine hook size needed and yarn weight and for desired size. Helpful notes and pics as well. It is a paid pattern and definitely worth the price.
For this project I used two hooks an N-15, 10.0mm and P-16, 11.5mm and 3 strands of yarn. (One of the Homespun and 2 of the Unforgettable). I used the larger hook until I got to shell section, then switched to the smaller hook. PAY ATTENTION to the MM SIZE OF THE HOOK you are using rather than the letter size. My P hook was a larger mm size than the P hook listed in the chart. This is why I switched to my N hook when the piece became too large around.

I increased until 40 stitches around. (one extra increase round) Made until length from base of fin = 27”. Added a tie with 3 strands of yarn chain length of 140.

I used about 1 1/2 skeins of the Homespun and 2 full skeins of the Unforgettable for the 4,5,6 size.