I haven't seen the t-shirt in question, but does your boss know what constitutes a racist? Racists are people who believe that their race (or ethnicity) is better than the others. Being proud of one's race does not necessarily constitute racism unless one states it is better than all the rest. Of course White's may make claims like that... but since it would be for their drysuits rather than a race or ethnic group, it hardly constitutes racism as you demonstrated to the dimwit... er, boss.