Personalized 3rd Birthday Sailboat Youth T-Shirt. 3rd birthday sailboat Youth T-Shirt - Black with number 3 on its sail makes a fun nautical themed party day gift for a little boy. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.