Dataset: Log for the samples taken using the Underway system on board of the R/V Atlantis during the CliOMZ AT50-10 expedition from Golfito, Costa Rica to San Diego, USA that occurred in May - June of 2023.

A system with a Geotech in-line acrylic filter holder (142mm diameter) connected to a flowmeter was attached to the Underway water flow on R/V Atlantis and particulates were collected for approximately one hour. The filtration system was arranged to split the water flow between two filter holders/flowmeters to achieve dual sampling from the same water mass. One side contained a combusted Glass Fiber FIlter (GFF) and the other side fractionated the sample with a 51um pore size Nitex mesh and a 0.2um pore size Supor (PES) filter. The Nitex and Supor filters were cleaned with 5% for 4 hours and neutrilized to pH6 before use. Samples were collected at station and while on transit (between stations).

A Geotech in-line acrylic filter holder 142mm diameter was used along with a flowmeter for this dataset.