Keller began his lifelong fascination with manta rays on August 13, 1985 when he logged his 63rd scuba dive and his first manta ray night dive in front of the old Kona Surf Resort at Keauhou Bay, currently the Outrigger Kona Spa and Resort. 

A Professional Association of Diving Instructors (PADI) Open Water Scuba Instructor, Keller moved to Kona, Hawaii in 1991 and began working full time at Jack’s Diving Locker where he met his future wife, Wendy.  In 1993 Keller and Wendy, co-authored the PADI Manta Ray Diver Specialty Certification which he has been teaching ever sense at Jack’s.

In 2003 the Laros’ co-founded the Manta Pacific Research Foundation and along with a core group of manta ray enthusiasts began to pursue the mission of research, education and conservation regarding manta rays.

Between 2003 and 2009 Manta Pacific was instrumental in the creation and finally the enactment of Act092(09) making it illegal to kill or capture manta rays in the State of Hawaii since 2009.

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Beginning in December 2012, at the behest of the Hawaii State, Department of Land and Natural Resources, Division of Boating and Ocean Recreation, Keller facilitated ten meetings of Kona Manta Tour Operators and helped created the Manta Tour Operator Standards.  These voluntary standards represent the best practices for the industry and were presented to the community in 2013. In January 2013, during a manta ray night dive, a Bottlenose Dolphin tangled in fishing line approached Keller who was able to free the animal.  Video shot of the event went viral and has been widely viewed on manta media platforms.

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In September 2014, Keller was guest speaker at Hawaii Community College – Office of Continuing Education and Training’s Manta Naturalist Course for Manta Tour Guides and Operators.  In 2014 Keller received a PADI “Certificate of Recognition for Passion, Loyalty, Quality of Service and Education”.  

In 2017 he was recognized by Sport Diver Magazine as the Sea Hero for July.

Since 2017 Keller has advocated for increased safety and sustainability measures for the manta ray tour industry on Hawaii Island and throughout the state.  He continues to teach the PADI Manta Ray Diver Certification class through Jack’s Diving Locker and has logged over 14,200 open water scuba dives.