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The availability, specialization and adaptability of the offshore wind survey fleet face growing scrutiny amid accelerating demand. What’s emerging is a fragmented but evolving fleet comprising a mix of purpose-built and retrofitted units alongside a sizable number of unmanned surface vehicles (USVs).
As offshore wind and oil and gas are increasingly competing for limited survey capacity, understanding where and how demand is rising is critical for developing robust strategies.
Here we share some of the key takeaways from our Q1 2025 edition of the ‘Offshore Wind Survey Vessel Supply and Demand Outlook.’
Vessels included in the study
Three main categories of survey vessels were analyzed in this study: the survey marketed fleet, unmanned surface vessels and geotechnical assets. It should be noted that seismic vessels equipped for 3D seismic data collection in oil and gas exploration were not included.
- Survey-Marketed: vessels designed for geophysical survey tasks that deploy towed equipment for seabed mapping (MBES, SSS, UXO etc.). These vessels also use ROVs for underwater imagery.
- USVs: these vessels use various technologies to navigate, collect data, and perform a range of geophysical and bathymetric surveys without an onboard human presence. Acquisition tools, like those used in the manned fleet, are available except for unexploded ordnance. It should be noted that USVs are a developing technology, albeit a fast-scaling one. Due to lower technical limits they are most suitable for near-shore projects.
- Geotechnical assets: These vessels are used for offshore geotechnical investigations and site surveys to provide data about seabed conditions. Cone penetration testing (CPT) equipment is used for a specialized category of geotechnical survey while vessels with heavy-duty drilling systems are used for coring and deep geotechnical sampling.
The market is adapting to rising demand
Demand analysis has uncovered a steady upward trend in offshore wind survey activity. In 2019, offshore wind surveys accounted for a total of 14,068 vessel days but this number grew to 26,748 during 2024. This represents a 90.1% growth over just five years. When analysis is categorised by vessel type, further insights are revealed.
- The geotechnical market experienced a 75% increase in vessel days between 2019 and 2024.
- Growth was the same in the general survey market over the same time period at 75%.
- USVs were an outlier to the trend, going from virtually 0 vessel days in 2019 to 2112 in 2024, showing their emergence into this market.
Several vessel owners have reacted to this rising demand by converting Offshore Supply Vessels (OSV) into geotech vessels. To date, 16 Platform Supply Vessels (PSVs) have been equipped with CPTs. Fugro leads the fleet with 24 CPT-equipped units, followed by Gardline with eight and Geoqip with seven. Growth continues with three notable recent PSV conversions:
- GEOQUIP SILVRETTA (Geoquip) - under conversion at Green Yard, Norway.
- GEO POWER (PDE Offshore) - conversion completed in late 2024, vessel currently supporting Taiwan’s offshore wind sector.
- FUGRO ZEPHYR (Fugro) - under conversion in Gdansk, Poland.
The use of geotechnical vessels is set to become even more prevalent due to the strength of the offshore wind project pipeline.
The survey work scope break down
There are four primary work scopes undertaken by survey units: inspections, stationary surveys, geophys surveys and hydrographic surveys. Of these scopes, inspections are currently contributing to the vast majority of demand.
This is how it breaks down:
During 2024, 32% of vessel days were attributed to on-site inspection and construction support during wind farm installation and operations phases. A further 32% were for state-led hydrographic surveys undertaken prior to site award. Two types of survey have been observed during the permitting phase:
- Survey Geophys (15% of vessel days): characterized by regular, grid-like patterns–a marker of towed equipment.
- Survey Stationary (23% of vessel days): involving seabed imagery with ROVs, geotechnical sampling, CPT and environmental surveys such as bird observations.
An increasingly global market will pressure the fleet
In terms of survey activity, the mature Northern Europe market is seeing its total share of survey demand decreasing. Meanwhile, a new contingent of Mediterranean projects began permitting in the late 2020s and could require a large number of survey vessels. To the east, offshore wind demand in APAC is steadily growing, but so far the total survey volume per project is observed as being smaller on average. Frontier markets will further expand global demand.
Geotechnical vessels show the fastest near-term demand growth, reflecting the volume of projects in permitting. Meanwhile, USV/ASV (autonomous surface vehicles) assets also show increased demand but this is driven by vessel owners rather than developers due to the advantages of these new technologies.
It should also be noted that in the near future offshore wind and oil and gas (O&G) site surveys will compete more intensely for specialized vessels and equipment. Growing demand from both sectors will put pressure on supply chains and could potentially lead to higher costs and scheduling constraints.
The client pool is becoming more diverse
Spinergie has observed that the top 10 developers, and the most ambitious countries, have totalled over half of all demand during the last decade. But, while those top developers have increased survey volume, the demand of newer companies and countries has grown even faster.
These insights are part of a broader study, encompassing a supply analysis, detailed demand forecasts and a supply demand comparison across key vessel scopes. Contact us to receive the full study or a custom survey forecast: insights@spinergie.com
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