Gelcoat and more at build

[Stuart 28-2]

Photo is a blister under repair.
My understanding is the builder sprays gelcoat into the mold. They get the blue stripe by taping that part off and spraying with gelcoat colored white. Then remove the tape and spray with gelcoat colored blue. Then they layer in the fiberglass to produce the hull (simplified due to level of understanding).
I thought they just went down to the water line with gelcoat. This blister is well below the water line. However, just going by the colors and their order, it looks to me like what I label as 1 is the same gelcoat as above water line and what I label as 2 is the same blue as the stripe.
Please comment in whether that is true or something else.
The follow up question is what is the lighter colored blue that I label as 3?
It seems like that is the first layer outside from the white "gelcoat". Is that a barrier coat of some kind that would have been applied by Ericson at build prior to bottom paint?

 

[Parrothead]

The gelcoat application process is very close to your description and this may explain why you're seeing 3 distinct layers:

1. The hull mold was first waxed for release.
2. The stripes were masked.
3. The entire mold was sprayed with hull color.
4. The stripe masking was pulled exposing the mold where the stripes will be.
5. The exposed areas were sprayed with stripe color.
6. The entire hull was sprayed with backup gelcoat. The backup gel could have been purchased as a separate product but my experience was the mold shops would save the left over uncatalyzed gelcoat in community drums and that amalgamation was used as backup gelcoat.
7. The lamination schedule began following the backup gelcoat.

The purpose of backup gelcoat was to provide added thickness to the gelcoat layer and to provide opaqueness to the finished lamination. Seeing sunlight through the hull was unnerving to customers and the backup eliminated that. If only the darker stripe gelcoat was saved for backup (that was my experience) the amalgamated color was somewhere between olive drab and gray.