The United Kingdom Directory of Marine Observing Systems (UKDMOS), is a unique internet-based searchable database of marine monitoring conducted by UK organisations.

Aiming to fulfil the basic requirement to know where, when and what is being monitored in the marine environment around the UK and provide information to help coordinate monitoring across different organisations, UKDMOS is a tool for searching monitoring programmes and series based on information such as the parameters measured or the frequency of measurements taken.

UKDMOS is managed and updated by the Marine Environmental Data and Information Network (MEDIN).