In a statement issued by a family member, Sam's parents Jo and Andrew said they were "devastated".
"Sam left us far too soon, and while words will never fully capture the light, joy and energy he brought into our lives, we hold on to the memories that made him so special," they added.
Sam's parents said he was "adored by his family" and described him as "loyal, funny and fiercely protective".
They added the Race Across the World experience "opened Sam's eyes to the wonder of adventure".