They list that he married first Joan -?-, and second to Mary -?-, [who may have been a sister to Henry WATERS/WATE/WALTERS] and was the John GATER who died in 1652 in Maryland.
They also state for the John born ca. 1620 in a footnote that "Also appearing on the list, although not in proximity to them [Jo. GATER age 36, Joan GATER age 23] was Jo. GATER, age 15. It was previously assumed he was the son of an earlier marriage of John GAITHER and was the John who moved to Maryland, but the Lower Norfolk County records in the years after he would have reached his majority do not indicate there was more than one John there.This John may have died or have returned to England.No land is known to have been claimed by him or others for his adventure to Virginia."