This deliverable reports on WP6 calibration and validation tests for six cost-effective instruments developed in WP4 that measure variables related to physical, chemical, and microplastics Essential Ocean Variables (EOVs) and Marine Strategy Framework Directives (MSFDs). Each instrument - different sensor and sampling technologies - was tested under realistic experimental conditions to document performance in terms of how well sensors measured variables of interest and how well samplers collected targets of interest. This was an important step to ensure that instruments performed according to the needs and requirements of demonstration activities in WP7, both in terms of withstanding operations with seawater or submerged in seawater, and also that variables of interest were sufficiently measured and sampled