Wash the cucumbers thoroughly under cold water. Slice them in half lengthwise and scoop out the seeds. Chop into bite-sized pieces, sprinkle with salt, and let sit for 10 minutes. Rinse and dry.

Gently break the imitation crab meat into small flakes and set aside.

Peel and dice the avocados, tossing immediately with lime juice to prevent browning. Add to the bowl with the crab.

Whisk together mayonnaise, rice vinegar, sesame oil, soy sauce, and sriracha in a small bowl. Adjust according to taste.

Combine cucumbers, flaked crab meat, and diced avocados in a larger bowl. Fold gently to mix.

Dress the salad with prepared dressing and toss gently to coat, being careful not to mash the avocado. Sprinkle with sesame seeds and nori if using.

Cover and refrigerate for at least 30 minutes before serving.