In a bowl, mix the fresh lime juice with a pinch of salt. Add the peeled and deveined shrimp to the lime juice mixture, ensuring they are fully submerged. Let the shrimp marinate in the refrigerator for about 15-20 minutes, or until they turn opaque.

While the shrimp is marinating, prepare the vegetables by thinly slicing the cucumber, red onion, and jalapeño pepper. Place them in a large mixing bowl.

After the shrimp has marinated, drain off some of the lime juice, leaving about 2 tablespoons in the bowl with the shrimp. Add the marinated shrimp to the bowl with the sliced vegetables.

Gently toss the shrimp and vegetables together. Add the chopped cilantro and diced avocado, then season with salt and black pepper to taste. Toss again to combine all the ingredients well.

Allow the aguachile to sit for about 5 minutes to let the flavors meld together. Serve immediately, accompanied by tortilla chips for scooping.