A little push can make things interesting. :P
In order to work faster, I used a basic brush for the sand and some colors filled with vectors for the ocean. Then, I used a different brush on the edge of each layer so the result can be more natural. The most tedious part was cleaning the drawing before starting with the colors because it had so many scratches. But it was fun to draw, specially Pinkie's wide hips.
Fun fact: Fluttershy's top bikini is entirely based on the design of the bikini that wears Minamoto Raiko, a character from the Fate series.
sketch

ink

At this point, I have to take this shipping to the next level. Not necessarily in the NSFW territory, but trying to justify it with a short story. I have an idea which is:
-Applejack convincing the two to go out together
-having these two together in front of a sunset
-Dashie playing the guitar and singing Loyalty
-then having Lightning Dust to cause some problems (because she didn't get in the Wonderbolts because of Dashie)
-Rainbow is hurt and she's on a hospital (Fluttershy is with her)
-Dashie confess to Fluttershy
-Happy ending
After that, I think it would be nice to make Flutterdash fanart in a way that Dashie isn't shy anymore.
That's overall my plan with these two. The first version of this story was much longer and I didn't like it.
Welp, I hope you like it and thanks for your support!
Love,
RT