Sula 2 Compact Unmanned Surface Vessel

Sula 2 is a battery-electric unmanned surface vessel in the 1.7–2.5 m class that travels in a van or on a small trailer and launches with two people. It is the smallest of our platforms for survey-grade multibeam with its own INS and sound-velocity profiler, such as an R2Sonic Sonic 2020-V or a Norbit WBMS, and it also takes a light towed side-scan, a stabilised thermal camera and mesh radio for harbour and coastal work. We configure each boat to order from a hull in this class, with RTK GNSS position and dual-antenna heading as standard.

Platform specification

The figures are ranges across hulls in this class.

	Hulls in this class
Length	1.7–2.5 m
Hull and propulsion	Battery-electric; catamaran or triple hull
Endurance	4.5–20 h
Typical speed	Survey 2 kn; maximum 4–4.5 kn (9.7 kn on one hull)
Payload mass	27–91 kg
Water	Sheltered and coastal water: harbours, nearshore and cable landfall
Transport and launch	A van (modules under 20 kg) or a small unbraked roller trailer; two-person launch
Comms	5 GHz MIMO broadband radio or WiFi, and 4G; maritime broadband radio and VHF optional; a mesh (MANET) node fits; Starlink for short missions
Standard navigation	RTK GNSS position with dual-antenna heading; a motion reference unit or survey INS added for multibeam
Optional anti-jam navigation	Base or Pro set; the Pro set’s flush-mount DVL needs a through-hull or a pole

Payloads Sula 2 takes

Everything Sula 1 takes also fits. Sula 2 adds:

Payload	Example models	Mount	Note
Survey-grade multibeam, with motion reference or survey INS and a sound-velocity profiler	WASSP S3; R2Sonic Sonic 2020-V; Norbit iWBMSh, WBMS; Teledyne SeaBat T20-P. Sound velocity: Valeport SWiFT; AML Oceanographic	Hull (pole or moon pool)	The head is light: a Sonic 2020-V head weighs 4.4 kg and draws 20 W on average. Roll and pitch, the mount, and power for the INS and logging computer decide the fit.
Side-scan sonar, light towfish	Blueprint Subsea StarFish 990F; DeepVision DE340/680 towfish	Towed (the StarFish also on a pole)	A light towfish on a hand reel. Heavier towfish with a depressor start at Sula 5.
Hand reel	JW Fishers CMS-1, CMS-2 (slip ring)	Deck	For a light tow.
Stabilised thermal camera or EO/IR gimbal	Teledyne FLIR M364, M364C, M364C LR; Trillium HD40; Octopus Epsilon 140	Mast	Our smallest platform for a stabilised camera or gimbal.
Mesh radio (MANET)	Silvus StreamCaster; Persistent MPU5; Microhard pMDDL2450	Mast	Mesh links between boats and the shore station.
Starlink	Starlink Flat High Performance	Mast	Short missions only: its draw is large against a battery hull’s payload budget.

At the edge of this class. A parametric sub-bottom profiler such as the Innomar SES-2000 compact weighs about 37 kg before its survey INS is added. That sits at the upper end of this class’s payload, so Sula 5 is the comfortable fit.

Where Sula 2 stops. Step up to Sula 5 for a towed magnetometer or gradiometer, a parametric sub-bottom profiler, a towfish on a reel with a depressor, and USBL tracking of a tow. Step down to Sula 1 when the payload is a single-beam sounder, an ADCP, a water-quality sonde or a hull-mounted side-scan and one person needs to carry the boat.

Applications

• Harbour, berth and channel multibeam. Full-bottom coverage of berths, basins, approach channels and dredged areas in sheltered water.
• Nearshore and cable-landfall survey along the coast, within a 4.5–20 h mission.
• Survey along quay walls and under bridges. Where GNSS is blocked, the anti-jam option is configured to keep the boat on its line.
• Port security and inspection with a stabilised thermal camera or EO/IR gimbal and AIS.
• Side-scan search with a light towfish on a hand reel.
• River current and water-quality work on longer missions than a portable boat runs.

The class works in sheltered and coastal water, for 4.5–20 h per mission.

Navigation

Standard: RTK GNSS position with dual-antenna heading, from a survey-grade GNSS heading receiver with light inertial (MEMS) aiding. The RTK correction feed comes from a base station on site or from network corrections over mobile data. The longer hull gives the two antennas a longer baseline. For multibeam, a motion reference unit or survey INS is added.

Option: anti-jam navigation, Base or Pro set. Both fit Sula 2, and it is the smallest of our platforms that carries the Pro set.

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

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. 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

Can a compact USV carry a multibeam with its INS?

Yes. Sula 2, in the 1.7–2.5 m class, is our smallest platform for survey-grade multibeam with a separate motion reference or INS and a sound-velocity profiler. The head is light: an R2Sonic Sonic 2020-V head weighs 4.4 kg and draws 20 W on average. Roll and pitch, a pole or moon-pool mount, and power for the INS and logging computer decide the fit.

Can a compact USV tow a magnetometer for UXO survey?

Towed magnetometers start at Sula 5. A magnetometer tow needs tow force and enough layback to keep the sensor clear of the hull’s magnetic signature. The smallest hull with a record of towing Geometrics G-882 magnetometers on offshore-wind UXO survey is 4.5 m long.

Can a compact USV carry a sub-bottom profiler?

A parametric profiler such as the Innomar SES-2000 compact weighs about 37 kg before its survey INS, which puts it at the upper end of this class’s 27–91 kg payload. Sula 5 is the comfortable fit.

Does a compact USV take Starlink?

For short missions. A Starlink Flat High Performance terminal draws a large share of a battery hull’s payload budget.

What anti-jam navigation fits a 2 m USV?

Both tiers. Sula 2 is our smallest platform that carries the Pro set: a multi-element CRPA with null-steering, a tactical-grade fibre-optic-gyro inertial unit and a flush-mount DVL, which needs a through-hull or a pole.