Captain Stephen Polk, MNI
Director, Maritime Education & Training
Captain Stephen Polk supervises SCI’s Center for Maritime Education. Before joining SCI, he was a Senior Port Captain for Kirby Inland Marine, LP and managed several types of inland towing vessels in the Canal Division. Captain Polk is a certified Crew Endurance Management System (CEMS) expert and holds a United States Coast Guard 3rd Mate Unlimited Tonnage, Oceans License. He also recently earned his Master of Towing Vessel and 300 ton Master-Oceans endorsement on his license.
A veteran of Operation Iraqi Freedom, Captain Polk served in the US Navy with two patrol boat units. As a Lieutenant Commander (LCDR), he has worked in various leadership and supervisory roles such as Tactical Communications Officer, Training Department Head, and Operations Department Head for both of the patrol boat units he was assigned to. Captain Polk has also logged over 10,000 hours of tactical and underway command experience while protecting ports and performing escorts of MSC and Navy warships in and out of various harbors worldwide.
Captain Polk started in the maritime industry as an Able-Seaman (A.B.) for Polar Tankers and as a Third Mate and working in the TAPS trade moving crude oil from Valdez, AK to various ports along the west coast of the United States. He graduated from Texas A&M University at Galveston in 1997 with a B.S. in Marine Transportation.
Captain John Arenstam
John Arenstam retired from the U.S. Coast Guard with the rank of Captain after 27 years active duty. He served in Coast Guard ships all around the country, sailing along every coast and all 5 Great Lakes. His assignments included Captain of the icebreaker PENOBSCOT BAY on the Hudson River, and the seagoing buoy tender FIREBUSH out of Kodiak, Alaska.
Capt. Arenstam spent most of his Coast Guard career in waterways management, aids to navigation and bridge administration at offices in Virginia, New Orleans, and Washington DC, and aboard "black hulls" around the nation. John represented the USCG at the International Association of Aids to Navigation and Marine Authorities (IALA). During his time in Washington he worked for the USCG Director of International Affairs, and gathered considerable worldwide exposure, while conducting analysis and training overseas. John most recently served as the Deputy Sector Commander in New Orleans and as the Director of Western Rivers for the Eighth Coast Guard District.
John graduated from the US Coast Guard Academy in 1987 with a BS in Mathematics and earned his MS in Operations Research from The George Washington University in 2001. John is married to Rose and they have three children, Joshua, Julia and Jacob.
Administrative and Marketing Assistant, CME-Paducah
Originally from Columbus, GA, Kelly has been with SCI's CME-Paducah since November 1997. Prior to that she worked at AFLAC worldwide headquarters in the Conventions and Meetings Department. Kelly graduated from Rhode College in Memphis, TN with a major in political science and a minor in history.
Captain Thomas Chivers
Captain Thomas Chivers worked in the inland river industry for over 30 years. Starting as a deckhand and working his way up to Captain, he spent over 25 years in the wheelhouse. Thomas has worked on the vast majority of the inland waterways and Western rivers, and holds a Master of Towing on Inland Waterways (MMC). Thomas spent five years as a trip pilot, and joined SCI’s Center for Maritime in Education as an Instructor in January 2018.
Captain David T. Howell
Having worked on the waters for three decades, and the majority of that time as a captain, Captain David Howell brings wide-ranging experience and knowledge to his position as Simulator Instructor at SCI–Houston. A lead or senior captain for most of his career, for 24 years Captain Howell worked on supply boats, offshore towing boats, and wire boats. He has experience up and down the east coast, gulf coast, and many ports internationally. Capt. Howell spent several years at John E. Graham & Sons, Mag Marine Service, Brown Water Marine, Bud’s Boat Rentals and North Bank Towing training and mentoring younger mariners. Before joining SCI he worked as Lead Captain at Buffalo Marine Service, where his leadership impacted the budding careers of many towboat crews.
With training in first aid, water survival and hazmat, Captain Howell holds a number of licenses and certifications, including US Coast Guard Master 200 Ton Near Coastal, US Coast Guard Master of Towing Vessels, Western Rivers and Inland Waters, and Unlimited Radar. He is a US Coast Guard Designated Examiner and a Qualified Assessor.
Simulation & Database Manager, CME-Houston
Matthew Hyner brings his background in computer graphics and multimedia development, specializing in the use of real-time 3D computer environments and Geographic Information Systems. A graduate of Pratt Institute’s department of Computer Graphics and Interactive Media, he has worked over the years on simulation projects focusing on urban planning, architecture and training in the past for several government agencies, educational institutions, and private corporations including The FAA, US Air Force, Department of Transportation, Federal Transit Authority and Housing and Urban Development.
Since joining SCI, he has worked with CME’s instructors and training partners to upgrade, and develop new areas and vessels to be used on our simulators in Houston and Paducah. With his experience working in the Architecture and Engineering community, Matthew has been able to assist several engineering firms who have contracted SCI to assist them by conducting feasibility studies for several maritime construction projects which posed possible hazards to marine navigation and safety.
Captain Kelly F. Jones
Captain Kelly F. Jones brings nearly ten years of experience in the maritime industry to her role at CME Houston. Most of her experience has been on towboats pushing chemical barges on the Western Rivers, Gulf Intracoastal Waterway, and inland waterways where she previously worked as Relief Captain for Kirby Inland Marine.
Capt. Jones graduated with a BS in Marine Operations from New York Maritime College. She brings a scope of knowledge spanning both inland and offshore aspects of the industry. Her licenses include: Master of Towing, Great Lakes, Inland Waters, and Western Rivers; Master Unlimited, Inland Waters; and Second Mate Unlimited, Oceans.
Business Relations Coordinator, CME-Houston
Lisa came to SCI in 2016 to spearhead the development of the e-learning program. She brings her knowledge of digital media and online learning, along with almost 10 years of experience of the maritime industry. Lisa previously worked at CDP and Kirby Inland Marine. While at CDP she worked closely with SCI to support CME customers as they completed their annual training, so joining SCI is a natural step for her.
Graduating with a BA in Religious Studies and Ancient Mediterranean Studies at Trinity University, Lisa is currently in the process of attaining a Master's in Digital Media at University of Houston – Clear Lake.
Captain Ernest “Ray” Sexton
A longtime US Coast Guard veteran and inland waterways pilot, Captain Ernest “Ray” Sexton joined SCI–Paducah as an instructor in January 2015. He brings four decades of experience in coastal and inland waterways navigation, search and rescue, law enforcement and port security to his teaching role.
Captain Sexton spent thirty years in the US Coast Guard with postings from Hawaii and Alaska to Alabama, Florida, Georgia, Texas and Tennessee. His duties ranged from buoy tending to search and rescue—a responsibility that resulted in dozens of lives saved over the years. Following 9/11, Captain Sexton helped secure the ports of Savannah and Charleston, South Carolina. He has received several awards for his service, include the Coast Guard Commendation Medal with three gold stars, the Coast Guard Achievement Medal with gold star and the Commandant’s Letter of Commendation Ribbon with gold star.
Upon his retirement from the Coast Guard, Captain Sexton joined American Commercial lines as a relief captain and worked for Parker Towing Company before joining SCI. His licenses include Master of Towing Vessels and Master of Steam or Motor Vessels up to 200 tons domestic or 500 tons (ITC) upon Inland Waters and Western Rivers.
Captain Jeff Stover
Capt. Jeff Stover has been in the inland river industry for 36 years, working his way up from deckhand to Captain. He became a Port Captain in 1998, based in Operations and working closely with the USCG and ACOE. In 2012, Jeff was promoted to Senior Port Captain, working in the Regulatory division and managing licensing, the Steersman Program, and SCI training. Jeff joined SCI's Center for Maritime Education in February 2018.
He has been married to his wife Denise for 31 years and they have two children, Peyton and Avery. Jeff and his family live in Reidland, KY.
William (Buck) Viniard
Building Facility Coordinator and Simulator Operator, CME-Paducah
Buck has been employed with SCI’s Center for Maritime Education since the opening of the Paducah facility in 1997. In addition to Buck’s current position as Building Facility Coordinator and Simulator Operator, he also maintains a level 2 maintenance certification on the Polaris simulator. Buck is actively involved with the emergency services: he is a 26 year, 400+ hour certified Firefighter, and was an EMT with his local ambulance service for 20 years. Buck has been married to Carissa, his wife of twenty-eight years and has two sons, Tyler and Cody.