Understand
Compare the specifications that change which part fits your application.
Open the selection guidesEngineering notes
What we have learnt building this kind of hardware.
Practical guidance for teams designing underwater vehicles, ROVs, AUVs and marine-robotics systems. Each article connects selection criteria with relevant Blu-Sub components available through Vebix Automation.
The engineering notebook
Read. Calculate. Specify.
Choose a route to continue.
Calculate
Work through depth pressure, buoyancy, thrust and cable voltage drop.
Use the engineering calculatorsSpecify
Organise your application and constraints into a component enquiry.
Create a selection reportSelection and reference
Twenty-three guides, written by the people who specify.
Selection and reference material across UAV avionics, UAV propulsion, subsea systems and defence engineering. Each one connects a decision to the components it applies to, and states what it is based on.
UAV avionics
Flight controllers, positioning, power sensing, radio links and companion computers.
UAV positioning
Drone GPS, RTK and dual-antenna heading: which do you need?
Choose drone GNSS by positioning and heading needs. Compare standard GPS, RTK corrections and dual-antenna yaw, with a Holybro sourcing checklist.
Read article →Avionics compatibility
Analog, digital or DroneCAN: choosing a Pixhawk power module
Match a Pixhawk power module to its controller: analog sensing, I2C digital sensing and DroneCAN, plus voltage, current and wiring checks before ordering.
Read article →Fixed-wing sensing
Choosing an airspeed sensor and pitot tube for a fixed-wing UAV
Choose a fixed-wing or VTOL airspeed sensor: airspeed versus GPS speed, I2C versus DroneCAN, pitot installation and the details needed for a quotation.
Read article →Flight controller comparison
Pixhawk 6C, 6C Mini, 6X or 6X Pro: which flight controller should you choose?
Compare Holybro Pixhawk 6C, 6C Mini, 6X and 6X Pro: integrated versus separate baseboard, case and variant options, and an exact-SKU checklist to order from.
Read article →Ground-station links
How to choose a UAV telemetry radio: data rate, range and ground-station compatibility
Choose a UAV telemetry radio: RF versus serial data rate, a worked 915 MHz link budget with cited SiK sensitivity, antennas and ground-station fit.
Read article →Onboard autonomy
Building an AI research drone: integrating a companion computer with Pixhawk
Integrate a companion computer with Pixhawk: responsibility split, serial and Ethernet links, separate power, cooling and a bench-test checklist.
Read article →Research platforms
Holybro S500, X500 V2 or X650: choosing a drone development kit for research
Compare Holybro S500 V2, X500 V2 and X650 drone kits: wheelbase, included propulsion and avionics, frame versus ARF versus development format.
Read article →GPS-denied navigation
Optical flow, lidar or visual odometry: holding position when GPS is unavailable
Navigating without GPS: what optical flow, a downward range sensor and visual odometry each measure, where each fails, and what a working indoor stack needs.
Read article →UAV propulsion
Motors, speed controllers and the protocols that connect them to an autopilot.
Propulsion control
Choosing a drone ESC: PWM, DShot, telemetry and programming compatibility
Choose a drone ESC by control protocol, telemetry path and firmware family: PWM versus DShot, BLHeli-32 versus AM32, configuration tools and troubleshooting.
Read article →Subsea systems
Thrusters, pressure housings, buoyancy, sealing, lighting and depth measurement.
Buying guide
Underwater and ROV thrusters in India
Authorised Blu-Sub propulsion options, quote planning and the information needed for a useful thruster enquiry.
Read article →Selection guide
How to choose an underwater ROV thruster
Compare thrust, voltage, depth rating, ESC configuration, rotation direction and integration requirements.
Read article →Selection guide
Subsea enclosure selection for marine research payloads
Depth rating and material trade-offs, O-ring compound and gland sizing, pre-deployment testing and internal fit-out.
Read article →Engineering guide
Buoyancy and ballast for ROV and AUV research platforms
Net buoyancy calculation, syntactic foam selection by depth rating, ballast trimming, and how enclosure and thruster choice affect the budget.
Read article →Underwater imaging
ROV lighting: reducing backscatter before adding more lumens
Plan underwater ROV lighting around camera distance, beam placement, dimming and power. Includes a Blu-Sub light example and a repeatable in-water test.
Read article →Subsea instrumentation
How to choose an ROV depth sensor: pressure range, accuracy and interface compatibility
Select an ROV depth sensor by pressure range, overpressure limit, accuracy and interface. Compares Blu-Sub M8, M10 and M14 sensors with a worked error budget.
Read article →Sizing method
How to size an underwater thruster for an ROV
Size ROV thrusters from drag, target speed and vectoring angle. Worked method for thrust per unit, thruster count and the margin real vehicles need.
Read article →Comparison
Cable penetrator versus underwater connector
When to use a subsea cable penetrator and when to use a wet-mateable connector: cost, serviceability, depth rating and failure modes compared.
Read article →Comparison
Aluminium versus acrylic subsea enclosures
Head-to-head comparison of aluminium and cast acrylic subsea pressure housings: depth rating, optical access, thermal behaviour, servicing and cost.
Read article →Reference
Subsea pressure and depth conversion guide
Convert depth to pressure in bar, psi, MPa and atmospheres. Reference table, the formula behind it, and how depth ratings and test pressures relate.
Read article →Design walkthrough
Designing a 300-metre ROV propulsion system
End-to-end propulsion design for a 300-metre ROV: thruster count and layout, bus voltage, tether losses, sealing and how it feeds the buoyancy budget.
Read article →Worked example
ROV buoyancy and ballast calculation, worked through
A worked ROV buoyancy and ballast calculation: net buoyancy from mass and displacement, foam volume for a target trim, and how to measure displaced volume.
Read article →Defence engineering
Harness acceptance testing and instrumentation for field and defence trials.
Checklist
Military cable harness testing checklist
A practical acceptance-test checklist for military and naval cable harnesses: continuity, insulation resistance, screening, optical loss and documentation.
Read article →Selection guide
Selecting data acquisition hardware for defence trials
How to select data acquisition hardware for defence and field trials: sampling, synchronisation, signal conditioning, ruggedisation and data integrity.
Read article →Engineering calculators
Free engineering tools
Run the numbers before you specify.
Several of the methods above are also available as calculators that run in the browser. Each states its formula and what it does not model, so you can check the figure rather than trust it.
Depth to pressure calculator
Convert water depth to gauge and absolute pressure in bar, psi, MPa and atmospheres, for seawater or fresh water. Free subsea engineering calculator.
Open calculator →ROV buoyancy and ballast calculator
Calculate net buoyancy for an ROV or AUV from mass and displaced volume, and the syntactic foam volume needed to reach a target trim. Free calculator.
Open calculator →ROV thruster sizing calculator
Estimate the thrust and number of underwater thrusters an ROV needs from frontal area, drag coefficient and target speed. Free ROV design calculator.
Open calculator →Cable voltage drop calculator
Calculate DC voltage drop, loss and cable resistance over a tether or harness run by conductor area or AWG. Free calculator for ROV and UAV power design.
Open calculator →Product selection report
Assemble a requirement into a structured brief you can download, print or send with an enquiry.
Build a report →