Personalized 3rd Birthday Sailboat Youth T-Shirt. 3rd Birthday Sailboat Youth T-Shirt - Black has colorful boat with number on its sail. This is perfect for a sailing themed party. 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.