If you want to step up his swimming experience, it is the right place to paddle. While the swimming speed has noticeably increased, the trains are also significantly more demanding. Personally, I can only speak for extensive breaststroke, but doing the paddles have intensified muscle strain outstanding. After 1000 m you now feels much underutilized than before and the structure of the condition seems to me better to go ahead. Generally I would however recommend a larger version as "S" Just covering a medium hand.