Fill a large pot with water, place over high heat and bring to a boil. Add some salt and the macaroni and stir. Boil macaroni for about 7 to 8 minutes stirring occasionally. Drain and set aside.
Place mayonnaise, tuna and vinegar in a small bowl. Season with salt and pepper and stir together.
In a large bowl combine macaroni, celery, carrot, red onion, and mayo mixture.
Fold together until thoroughly mixed together. Season with salt and pepper.
Place mixture in the refrigerator for at least an hour and season with more salt and pepper, as needed, before serving.
