Head, which is the parent company of Mares, has acquired Scuba Schools International (SSI), an ISO-certified provider of teaching material and education concepts for scuba diving instructors. Using 30 languages, it offers its services to some 2,600 diving schools and resorts in 110 countries. Founded in 1970 in Schwarzenbruck, Germany, SSI is one of the founding members of the Recreational Scuba Training Council (RSTC), an international organization that represents the interests of the diving industry.