"(5) Every watercraft trailer with a gross weight or manufacturer’s gross vehicle weight rating of three thousand pounds or more that is manufactured or assembled on or after January 1, 2008, shall have separate brakes equipped with hydraulic surge or electrically operated brakes on two wheels."

Not "ALL" trailers....just the ones which were built or manufactured after the grandfathered date....Jan. 1st, 2008 and the way I understand this is that surge brakes are still acceptable.