1. Bring a large saucepan, filled halfway with water to a boil with a generous pinch of sea salt.
2. Devein the shrimp then drop into the water with heads and tails on.
3. Boil until a few start floating to the top (about 5-7 minutes): Do not overcook or shrimp will be rubbery.
4. Drain the shrimp in a colander, then submerge in an ice bath to stop the cooking process.
5. Remove shells and tails, then slice shrimp in half, lengthwise.
6. To prepare the noodles: In large bowl, cover noodles with boiling water; let stand until softened, about 10 minutes.
7. Drain and chill under cold water; drain and return to bowl. Cut into two inch pieces.
8. Peel cucumber and slice with a mandoline slicer or use a sharp knife to cut as thinly as possible into long matchsticks.
9. Peel and pit avocado; cut into thin slices. Chop herbs.
10. Fill large shallow bowl half way with warm water. Dip each rice-paper wrapper into water until pliable, 5 - 10 seconds and pat dry on a clean kitchen towel.
11. Onto center of each wrapper place noodles, carrot, cucumber, mint, cilantro, basil, chives, and a single row of avocado and a single row of shrimp.
12. Fold bottom then sides of wrapper over filling; roll into cylinder.
13. Serve with sweet chili sauce for dipping.