Questions about rocker and tail shape

Hello, I’m starting to plan out a singlefin egg for my girlfriend(beginner) but had some questions on the rocker and tail shape. For the rocker, I thought that eggs generally used a pretty flat outline so as to plane and pick up speed better down the line (like a longboard) but as I researched different egg styles I saw more and more boards with varying rocker, so what kind of rocker would be “best” for learning proper technique. I chose the singlefin egg shape because I’ve heard a lot of talk about how it teaches you to turn correctly whereas a thruster can be forced into not-so technically correct turns. Continuing with this idealogy I’d like to make the rocker as user-friendly as possible. 

As for tail shape, I’d like to know what kind of dims I should be shooting for. Like how wide/thick is the tail at 2", 6", and 12" from the end.

thanks.

Rocker measurement, is a function of board length.     What are the dimensions of the intended surfboard?        Armed with that information, some meaningful comments can be offered.

I wonder if Thrailkill and other expert/pro shapers will also say bottom contours depend on board length.

I made an egg-ish 6-3 x 21.5 x 3.125 for myself and used a 10" single fin box set-up to just allow for a tri-fin (i.e., thruster) set-up with the center fin at 3.375" or greater.  Bottom was single to long double to vee (“Weirdo-Ripper” or “Sweet Potato”-ish bottom).

It worked as quad, thruster, and single, but by far best as quad, and the single worked but felt kind of slow and just not smooth & like a good single.  A well-known old skool shaper was out the day I was running the single (moving it around during session to try different positions) and his input was that the board at that length probably wouldn’t work well for me as a single if the bottom worked well for quad and thruster.  He said he doesn’t make single eggs under 6-7 in general, and that the bottom would usually be mostly flat, or have more of a hull-ish overarching concept.

I’m planning on 7’0" x ~20"(not sure on width)x2 1/2" 

How will adjusting the width affect the ride with the desired shape and length?

   For a 7 foot board, a natural rocker of 3 1/2 inches, nose and tail, would have the same rocker curve as a 9 foot board with nose and tail of 4 1/2 inches.       That kind of rocker is very forgiving.       Especially for beginners.     The rocker described above, hails from the balsa era, and was state of the art for decades.      Increases in board width, is the best way to increase both surface area and floatation.

I’ve noticed that some of the shapers who do longsboards for girls foil the noses a bit more - it makes them look like they have a flip in the nose rocker.  Kinda like a Simmons.    

My favorite template for a narrow midlength is McTavish’s “Carver” model, but I’d never use that bottom + a thruster setup for a novice surfer.   That template with Bill’s rocker + bottom + rails would be money for a novice of small stature surfing in beginner-friendly conditions.