Student athletes who are graduating can use this goodbye letter to express their thanks to a coach.
I can't believe we're done with my last season. You have been the best coach I've ever trained with. I feel like my skills in {sport} have progressed in leaps and bounds under your guidance.
Thank you for being so supportive and knowledgeable over the last {amount of time}. I'm so grateful for all of your help and I will miss you and the team.