T-shirt from BOS2023 can be ordered using the following link which includes more information.
ADDITIONAL T-SHIRT ORDER FORM 2023
Registered pilots in Class1, Class 5 and Club Class should only use this form if ordering additional T-Shirts as your own T-shirt is included with your entry fee and will be ordered based on the Size you included at registration.
Challenge entrants do need to order a T-Shirt (at a discounted rate) if you want one. Details on the form.