At 19, Howard jumped aboard a freighter ship and traveled to Israel where he dived the Red Sea for the first time.
While studying for his B A in Anthropology and Archaeology at the University of California in Northridge, Howard took a year off to study Archaeology at Tel Aviv University (1968) and it was there that he met his wife Sharon. There, he discovered ancient artifacts in the Mediterranean and explored the Red Sea coast in greater detail.
The Rosensteins started their first business in the ancient Roman harbors along Israel's Mediterranean coast in 1970. A year later, they expanded their operations to include the Red Sea base and opened one of the very first diving operations along the Sinai Coast of the Red Sea. In 1973 the Rosenstein's promoted their pioneering operation during a trip to Europe and the US. It was Howard's first experience as an Ambassador of Red Sea Diving where he was first introduced to Dr. Eugenie Clark and underwater photographer David Doubilet. The trio would eventually work together on eight National Geographic features over a span of 30 years.
The Yom Kippur War occurred in October 1973, and the area was evacuated and bombed. Business was put to rest until some years later when they slowly re-built and Sharem became one of the most popular diving destinations for divers. Film crews, diving and nature magazines, diving tourism companies and many famous people from the world over shared their Red Sea experience with Howard and his team.
The Sinai Peninsula where his dive center was located was returned to Egyptian sovereignty as part of 1982 Camp David Peace Treaty between Israel and Egypt. Howard then developed Fantasea Line a multinational live-aboard diving operation, taking divers the length of the Red Sea and as far as the exotic Indian Ocean atolls of Aldabra and Astove, in the Seychelles Islands.
Since then, Howard has developed underwater photographic equipment and invented and patented the ProEar diving mask. In 2002, together with his son Nadav, he created Fantasea Line, a company dedicated to making underwater photography affordable and fun. Fantasea Line is the world's leading Nikon Coolpix housing manufacturer as well as an industry leader in underwater photography accessories and lighting equipment.