Open water swimming is a core part of triathlon training, and a high-visibility tow buoy is one of those things experienced triathletes know they need but new ones often overlook. It keeps them visible to boats and other swimmers.
It's a practical gift that shows you understand they spend significant time in open water — and that you want them safe while they do it.
"Give it before their next open water training block or at the start of the season. It's not glamorous but it's genuinely useful — and it shows you've been paying attention."