In a large saucepan bring 2 cups salted water to a boil. Add rice; cover reduce heat to low, and cook until rice is tender and water is absorbed, 45-50 minutes.
Meanwhile, in a small bowl or liquid-measuring cup, stir together soy sauce, lemon juice, vinegar, and sugar until sugar is dissolved. Set sauce aside.
When rice has finished cooking, heat oil in large skillet over medium-high. Add shrimp, snow peas, and ginger; season with salt and pepper. Cook until shrimp are opaque throughout and snow peas are bright green, 2-3 minutes.
Divide rice among four bowls. Top with shrimp mixture and avocado; serve sauce on the side, or pour sauce directly over the rice bowl.