Since 2006, the Belgian Navy operates 5 Hydroid REMUS 100 Autonomous underwater vehicles. Four more were acquired in 2012 and 2016. 880 missions have been undertaken in various European countries for port protection and mine hunting operations, for which the sidescan sonar images are used,. This datset contains data from 455 missions (inland and testing missions excluded) from 2006 until 2019, mostly in Europe (Baltic, North and Mediterranean Sea) and contains ADCP, CTD, chlorophyll and turbidity data.

EMSO is a European network of seabed and fixed-point water column observatories whose scientific objective is to acquire long time series in the seas around Europe for the study of environmental processes related to interactions between geosphere, biosphere and hydrosphere. MAREGAMI project (MARine Earthquake Gap Assessment and Monitoring for Istanbul) is a bilateral Turkish-French collaborative project coordinated by IFREMER and Istanbul Technical University and funded by ANR and TÜBITAK. The goal of MAREGAMI was the development of new methods and monitoring strategies to assess earthquake and tsunami risks related to offshore faults, with tasks: (1) Marine geodesy: acquisition and processing of geodetic submarine data, (2) Hydrodynamics and specific depositional processes: water column data acquisition and hydrodynamic modeling, (3) Improving earthquake relocation with ocean bottom instruments, (4) Designing an optimal and sustainable network of submarine sensors. Data distributed here were acquired for MAREGAMI Task 2.  These consist of time series acquired during 4 deployments on the sealfoor perfomed between January 2018 and November 2020 of an instrumented frame holding a RBR bottom pressure recorder (BPR) and a Seaguard recording current meter (RCM) equipped with additional sensors (conductivity, oxygen, tide pressure end temperature). The acquisition and distribution of marine data time series in the Sea of Marmara is funded by EMSO-France Research Infrastructure, EMSO-Link, and MAREGAMI projet. DT-INSU provided operational support and instrumentation. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

Videoframe of seafloor displaying bedforms affecting sandy deposits in the continental slope of the Gulf of Cadiz, just downstream of the Strait of Gibraltar: a boulder indicating scouring by secondary helical flows formed from interaction with the current flow. Scouring creates a moat feature lateral to the sandy accumulation

Videoframe of seafloor displaying bedforms affecting sandy deposits in the continental slope of the Gulf of Cadiz, just downstream of the Strait of Gibraltar: isolated rocky boulder on a gravelly seafloor. The boulder acts as an obstacle to the bottom current, favouring the formation of a longitudinal sandy ribbon superimposed on a small scale and transverse asymmetric ripples. Note the sandy accumulation lee side of the obstacle as well as the two ripple patterns drawing a fishbone feature produced by secondary flows formed on both sides of the boulder. Additionally, note the fast transport and armouring by the MOW toward the ROV

Videoframe of seafloor displaying bedforms affecting sandy deposits in the continental slope of the Gulf of Cadiz, just downstream of the Strait of Gibraltar: A starved sand ribbon in a rocky area with superimposed smaller regular and asymmetric transverse ripples in centimetres. The sediment composition is mixed (biogenoeus and terrigenous) as is revealed by the different colours; the lighter colours comprise bioclastic debris located lee side of the ripples

Videoframe of seafloor displaying different bedforms affecting sandy deposits in the continental slope of the Gulf of Cadiz, just downstream of the Strait of Gibraltar. These bedforms are formed by the action of the Mediterranean Outflow Water which produces a complex patterns of bedforms from decametre to centimetre scales on the seafloor and remain poorly understood.