After some consideration, I decided the curved tail/wing would be more aesthetically consistent or continuous with total surfboard shape as a whole. Below are several figures (A-F) that evolved from the original, curved diagram "Stoneburner Tail (lol)". (The Stoneburner Tail does have a nice ring to it -- enough.) I rejected several shapes, including C-F. (Since that time I have played with more ratios and geometry -- new template array at bottom of page.)
For information about the original design (curved and angular variants) and the reasoning behind its development, click the following link:
http://bgboard.blogspot.com/2013/08/angular-dolphin-tail-or-wingtail.html
I felt the apex depth of the internal tail curve could range from 25-50% of the base template tail width. My gestalt was 40% of the base tail width is the appropriate curve depth. These shapes are the product of geometry, simple algebra and the artistic perceptions of the minds eye. If tail width is 13.23 inches. Forty (40) percent of that width would be 5.29 inches.
Base Plate Template. Tail section used for tail shape designs below.
A. This curved shape was taken directly from the original concept diagram (the red line curve).
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQ7pFPADF63DT5z65TZfkCr_kIQJD06c2omRJoG1tEZffnAjeiBSUxqdO6GP62NFz3YMElUQ1hIqtn1U3CKSHNT_D3_VU_y3ecg2NbFRTMi9uRbEvueiEqb9CKZ_beS_UVMxiX8GEikYRu/s1600/AKA_Stoneburner_6.jpg
B. This shape was derived from shape A.
C-F. Design variations of the original curve diagram.
C.
D.
F.
Updated Tail Template Array
I put together a tail template array (below) to compare a series of designs that use more specific ratios and dimensions than those above. Internal curve apex or depth is still the same percent of base-template tail width. The tail shapes in the array below are ellipse-based (click the following link).
http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-tail-templates.html
For information about the original design (curved and angular variants) and the reasoning behind its development, click the following link:
http://bgboard.blogspot.com/2013/08/angular-dolphin-tail-or-wingtail.html
I felt the apex depth of the internal tail curve could range from 25-50% of the base template tail width. My gestalt was 40% of the base tail width is the appropriate curve depth. These shapes are the product of geometry, simple algebra and the artistic perceptions of the minds eye. If tail width is 13.23 inches. Forty (40) percent of that width would be 5.29 inches.
Base Plate Template. Tail section used for tail shape designs below.
A. This curved shape was taken directly from the original concept diagram (the red line curve).
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQ7pFPADF63DT5z65TZfkCr_kIQJD06c2omRJoG1tEZffnAjeiBSUxqdO6GP62NFz3YMElUQ1hIqtn1U3CKSHNT_D3_VU_y3ecg2NbFRTMi9uRbEvueiEqb9CKZ_beS_UVMxiX8GEikYRu/s1600/AKA_Stoneburner_6.jpg
C.
D.
E.
I put together a tail template array (below) to compare a series of designs that use more specific ratios and dimensions than those above. Internal curve apex or depth is still the same percent of base-template tail width. The tail shapes in the array below are ellipse-based (click the following link).
http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-tail-templates.html