The Division of Ocean Sciences (OCE) of the National Science Foundation (NSF) announces that proposals will now be accepted for U.S. researchers to use the drill ship JOIDES Resolution to collect cores using the Advanced Piston Coring (APC) system up to sub-bottom depths of 100 meters to address research on multiple aspects of the ocean basins. This program, referred to as “JR100,” was outlined in a previous Dear Colleague Letter (NSF 17-018). This new NSF Dear Colleague Letter provides the specific dates and geographic area of operation for the first JR100 cruise and updates information previously provided on proposal preparation requirements. JOIDES Resolution is scheduled to be transiting from Papeete, Tahiti, to Punta Arenas, Chile, from 19 December 2018 to 18 January 2019. Approximately thirteen (13) days during this transit period will be available for cruise operations (including coring and site-to-site transit time) with the remaining seventeen (17) days allocated to the direct transit route between ports. The cruise participants will stay on the ship during the entire thirty days. For a successful proposal, the NSF science program to which the proposal is submitted will provide funding for the types of items normally included in an ARF-based coring proposal including, but not limited to, funding for PI and cruise participant salaries, core shipments, non-standard analytical equipment required at sea, and post-cruise research funding. Funding sources for the ship operations to implement successful proposals will be determined through conversations between cognizant NSF Program Directors.