Breadcrumb Photo Gallery Lake Michigan Limestone Shelves, Door Peninsula Limestone Shelves, Door Peninsula Last updated by System administrator November 16, 2008 Underwater fractured limestone shelves, off the east shore of the Door Peninsula near Rock Island, a reminder of the challenges and hazards of cruising this coast. Jim Caraway photo... Member Links Lifeline Newsletter Become a Member How to Join Member Benefits & Discounts Membership Application About the GLCC A Bit of History Contact Us Active forum topics Marine Survey NW MichiganWednesday in the GLCCSchool – USCG and Canadian Vessel Safety Equipment RequirementsThursday in the GLCCSchool – Marine Communications: How to Talk on a Marine RadioNow Available as a Recording in the GLCCSchool – Great Lakes Marine Weather Essentials Package – Part 4: Thunderstorm Primer/Creating Your Own Weather ForecastNow Available as a Recording in the GLCCSchool – Diesel 3: “I’m Cool but My Diesel Is Hot,” Marine Diesel Cooling SystemsMore