Technology has always played a major role in oceanography; new advances have changed how we observe the ocean. Among the many interests driving marine carbon observations, ocean acidification and marine carbon dioxide removal are at the forefront of research requiring better sensing options. There has been a recent explosion of interest in adapting existing technologies and developing new methods to provide much greater coverage of monitoring and better constraining the marine carbon cycle. As new players come to the field from various industries and backgrounds, we often field questions about why we don’t yet have commercially available in situ sensors for more biogeochemical parameters. There are many challenges to working in marine environments regardless of what we are trying to measure, and producing quality data on the time and space scales required for carbon cycle work is a huge task. Many clever people have faced these challenges with fervor and creativity, and we look forward to exciting new developments in this field.