Good one suzy2!
Perfect choice - a freestyle/wave is far superior to a freestyle for a child.
For adults, a freestyle has quicker acceleration - it has a wider, thicker tail. This is excessive for kids.
A child will accelerate quicker on a f/w - it has a much higher top speed, cuts through rough water far better and has a huge water state and wind range compared to the freestyle.
This board will teach him a lot, building up hours in the footstraps and harness in a wide variety of conditions. He will go faster than he ever has before, get his first air and a manageable board to start mastering the waterstart.
I am guessing you probably got about a 92l. The larger f/w boards have a option for 4 straps. This is a real bonus. After his skills and confidence improve, you can try 4 straps and a larger fin. This will help adopt a stronger, faster and more powerful stance and he will go faster again, now getting much closer to the speed of the adults.
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Freestyle wave 78 - the board that taught me planing carve gybes.
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Freestyle wave 78 - great for fast flatwater blasting and will even cope with a rogue wave!
suzy2, you will be amazed at the speed of his progress. You should be applauded for your leap of faith and for the $ you spent (and the time you will give). You will be SO rewarded in what you are about to witness!
If all goes well and he gets plenty of good quality sailing time then I think that as soon as next Christmas, Santa will probably realise that he deserves a 60 or 70l kids freestyle board. That's when the real show starts!
I have tried a lot of boards and sails so try me again if you have any other questions.
Rip it up!
Alex