Sailing through mud

The presence of mud in ports has been causing problems for years. High maintenance costs and limit draught. What if the draught can be increased and the maintenance costs can be reduced?

That is possible when sailing through the mud. The fluid mud can be compared to yoghurt or ketchup. The ship will feel some resistance (yield stress and viscosity of the mud), but no damage to keel or propulsion.

SEMASO has broad experience in investigating the implementation of ‘sailing through mud’ in the ports of Delfzijl, Emden and Liverpool. Groningen Seaports has increased her draught in the port of Delfzijl by sailing through mud. SEMASO has conducted the investigation for Groningen Seaports, resulting in the fact that vessels with a bigger draught can enter the port.


          Benefits of sailing through mud

Bigger draught – Increasing the maximum draught by several decimetres to meters.

Cost reduction – Reducing the quantity of maintenance dredging.

Optimisation – Implementing ‘sailing through mud’ can be optimised by an passive (present natural fluid mud layer) and/or active (conditioning the (consolidated) mud) approach.

Environmental – Possible present contamination can be reduced by an active approach (currently a PHD is investigating this).


SEMASO has the practical experience, knowledge, resources and network to investigate the implementation of ‘sailing through mud’ in ports for port authorities.

SEMASO is specialized in sediment management solutions for ports and navigational channels around the world.

Nautical depth implementation (passive and active)

Sediment dredging and reclamation

Physical and technical properties of sediment (e.g.: ripening, erodibility and consolidation)

SEMASO provides clear and practical solutions for the sediment problems, due to our up to date expert knowledge in the field, in house fieldwork and laboratory analysis, large network of experts, frequently consultations with clients and the ability to think practically.

All field, laboratory and consultancy activities are carried out according to the relevant ASTM or EU standards (e.g. NEN or BS) specified by our clients.

SEMASO is founded in 2016 as a sister company of the renowned Dutch company Wiertsema & Partners BV and Marine Sampling Holland BV (specialized in geotechnical investigations, laboratory analysis and geotechnical consultation) and in close cooperation with Ravensrodd Consultants Ltd (finding solutions to fine cohesive sediment problems). The HQ of SEMASO is situated in Tolbert in the Netherlands. The team of SEMASO consists of a number of experts, often the inventers of our generic Sediment Management Systems, and has acquired a network of experts within this field.






Laboratory Analysis


2017 – Feasibility study for Liverpool Docks – Phase 1 (UK)

2017 – Feasibility study for the port of Bushehr (Iran)

2017 – Sediment characterization in Breebaart polder (NL)

2017 – Erodibility of sand-mud mixtures at the bottom of tidal channels (NL)

2017 – Dispersion behavior of dredged sediment (NL)

2016 – Ripening factor –Determination of the ripening factor of dredged material

2016 – Leer (DLD) – Case study of the implemented under sediment pump

2016 – Ebrie Lagoon (Ivory Coast) – Laboratory analysis on sediment samples – BMT Argoss

2015 – Delfzijl (NL) – Phase 3 Second full scale field test – Sailing with negative underkeel clearance – Groningen Seaports

2015 – Watchet (UK) – Rheological investigation of harbour sludge



2017 – Sednet conference – Erodibility of sediment poster

2017 – Sednet conference – Sailing through mud poster

2017 – Sailing through mud VIDEO

2016 – Article Land + Water – Cost efficiënt maintenance dredging of mud

2015 – 4th MASHCOn conference – Publication ‘Sailing through mud’

2015 – Sednet conference – Sailing through mud poster