Sula 8 Offshore Unmanned Surface Vessel

Sula 8 is a 7.8 m diesel-electric catamaran unmanned surface vessel for missions of up to 24 h. It is our platform for the full UXO survey system: two tows, such as a Geometrics G-882 TVG gradiometer and an EdgeTech 4205 side-scan, plus an Innomar SES-2000 sub-bottom profiler with survey INS, USBL tracking and a powered winch. We configure each boat to order, with RTK GNSS position and dual-antenna heading as standard.

Platform specification

Sula 8 is a 7.8 m diesel-electric catamaran with a range of up to 300 km.

	Sula 8
Length	7.8 m
Beam	2.8 m
Height	2.5 m
Draft	About 1.0 m
Mass	About 2.4 t
Hull	Catamaran in polyethylene (PE) and other materials
Propulsion	Diesel-electric hybrid
Endurance	24 h at economic speed
Range	Up to 300 km
Maximum speed	8 kn
Comms	4G, 5G and satellite; communication distance up to 50 km, extendable by relay or satellite; remote control to 10 km
Water	Offshore, in moderate sea conditions
Working temperature	−10 to +55 °C

UXO survey configuration

Configured per project on Sula 8.

Tow lines	Two: a magnetometer gradiometer and a side-scan sonar
Gradiometer	Geometrics G-882 TVG (two G-882 sensors on a frame)
Side-scan	Towed, with reel and depressor
Sub-bottom profiler	Parametric, such as the Innomar SES-2000, with a survey-grade INS
Towed-body tracking	USBL
Handling	Powered winch
Mission length	Up to 24 h at economic speed

Payloads Sula 8 takes

Everything Sula 5 takes also fits. Sula 8 adds the full UXO stack and the deck equipment behind it:

Payload	Example models	Mount	Note
Towed magnetometer or gradiometer	Geometrics G-882, G-882 TVG; Marine Magnetics SeaSPY2, Explorer, SeaQuest2; SENSYS MX3D	Towed	The first of two tows, with the sensor 3–4 m above the seabed.
Side-scan sonar, second tow beside a magnetometer	EdgeTech 4205; JW Fishers 450/900 CHIRP with CMS-2 reel and DDW-1 depressor	Towed	The second tow. A hull-mounted side-scan is the fallback for a hull that cannot take two tows.
Parametric sub-bottom profiler	Innomar SES-2000 compact, SES-2000 standard	Hull	With a survey INS.
USBL for a towed body	Blueprint Subsea SeaTrac X150 with X010 beacon; Sonardyne Micro-Ranger 2	Hull	Positions the tows. Layback from a winch cable counter is the cross-check.
Powered winch	EIVA OceanEnviro 1.7 (650 m of 4.6 mm cable, 2 kN, slip ring)	Deck	The winch weighs 285 kg.
Iridium Certus satcom	Thales VesseLINK 200; Thales MissionLINK 700	Mast	The backup to Starlink beyond line of sight.

Step down to Sula 5 for a single magnetometer tow, a sub-bottom profiler or a towed side-scan in harbours and near-shore water.

Applications

• Offshore-wind pre-construction UXO survey.
• Cable-route UXO and geophysical survey.
• Offshore multibeam and sub-bottom survey.
• Water-column and metocean work: ADCP, sound velocity and CTD.
• Over-the-horizon operations with Starlink and Iridium Certus back to shore.

Sula 8 works offshore and launches from a harbour or a host vessel.

Navigation

Standard: RTK GNSS position with dual-antenna heading. One survey GNSS/INS is the reference for every sensor, with PPS time sync. The RTK correction feed comes from a base station or from network corrections over mobile data.

Option: anti-jam navigation. Pro is the natural tier for Sula 8, and the Base set also fits.

• Pro: a multi-element CRPA with null-steering, a tactical-grade fibre-optic-gyro (FOG) inertial unit, and a flush-mount surface-vessel Doppler velocity log (DVL) in a sea valve or bell housing.
• Base: a filtered anti-jam antenna, a compact inertial unit of industrial (MEMS) or lower tactical grade, and a compact DVL.

With either set, spoofing detection with automatic source switching is configured and integrated per boat, and integration with the autopilot is available. DVL bottom-lock needs the seabed within range, which means shallow and coastal water; in deep water the DVL falls back to water-track, and drift then depends on the inertial unit’s grade. More on the tiers: GNSS-denied USV navigation.

Integration and support

Integration	Payload fitted, wired and calibrated on the hull, with sensor offsets and parameters set and the RTK correction feed configured. Autopilot integration is available.
Delivery	Commissioning on your water, operator training, and support from our UK and EU teams.
Ordering	Configured to order, quoted per boat.

Questions and answers

What sensor height and track-keeping does a USV magnetometer survey need?

The towed sensor flies 3–4 m above the seabed, and 1–2 m line spacing needs track-keeping within ±0.5–1 m.

Which inertial navigation grade suits an offshore USV?

With survey payloads aboard, one survey GNSS/INS is the reference for every sensor. For anti-jam navigation, the Pro set carries a tactical-grade fibre-optic-gyro inertial unit, and the Base set also fits.