Prepare pasta according to the directions on the package; drain and rinse with cold water.
Set aside and let cool; about 5 minutes.
Transfer pasta to a deep salad bowl.
Add halved tomatoes over pasta.
Layer tuna over tomatoes.
Add sliced olives over tuna and set aside.
In a mixing bowl, whisk together minced garlic, lemon zest, pinch of salt, lemon juice, olive oil, water, salt and pepper; whisk until thoroughly combined.