Most likely in flatwater it just wont spin around as quick or slide around but itl let you turn sharper and have a little more high speed control i believe. Do you know if it was a kit or just home molded? Im not sure how it will affect surf with them but for freerifng you might want to consider deleteing them or buying a new square hull and transplanting or go straight to an RN hull and skip the square. Its all about persinal riding preference. I would try them out and see how they handle, You might like them ir decide there no good.