A rich mosaic of disparate crustal types characterizes the Earth beneath the sea. Although “normal” oceanic crust approximately 7-km thick is by far the most prevalent, abnormally thick oceanic-type crust of large igneous provinces (LIPs) also forms a significant component of the marine realm (e.g., Coffin and Eldholm, 1994; Mahoney and Coffin, 1997; Saunders, 2005). Scientific ocean drilling has significantly advanced understanding of LIPs. Herein we focus on significant outcomes of ten LIP-dedicated expeditions between 1985 and 2000 and also highlight prospects for future drilling efforts. The ten expeditions include three to the volcanic margins of the North Atlantic Tertiary Igneous Province, four to the Kerguelen Plateau/Broken Ridge LIP in the Indian Ocean, two to the Ontong Java Plateau in the western equatorial Pacific Ocean, and one to the Chagos-Maldive-Laccadive Ridge and Mascarene Plateau in the Indian Ocean (Table 1). Complementary geophysical and/or onshore geological investigations have added significant value to all of these expeditions.