"Proper surfing" is standard surfing as opposed to bodyboarding, bodysurfing, boogie boarding, or anything else that might be a variation of surfing.Or would it change the meaning?
In addition to the board being different, surfing involves standing up. You don't stand up in bodyboarding, thus it's seen as being easier to learn (at least, initially).Or perhaps "proper" means "strictly speaking", on a 'proper' surfboard, as opposed to the variations mentioned by Mridon.
This use of "proper" is correct, but not common in AE. And many people would confuse "can not do proper surfing" with "cannot surf properly", which is not what you mean. So in AE, I would use "actual" instead of "proper".Does the following sentence sound fine?
I can bodyboard but I can't do proper surfing.
Or should it be:
I can do bodyboarding but not proper surfing.