This document provides strategies to detect deepwater invasive species in the Northwestern Hawaiian Islands (NWHI) in support of the Papahanaumokuakea Marine National Monument (PMNM). The strategies use technical diving to conduct visual surveys and focus on two invasive species of growing concern, the octocoral Carijoa riisei and the red alga Hypnea musciformis. Both of these species are well established in the Main Hawaiian Islands (MHI), and managers and scientists are concerned they will negatively impact the relatively pristine marine ecosystems of the NWHI.