Need advice for large-scale lake surveying with a FIFISH V-EVO (mapping + environmental sensing)
Hi everyone,
I’m working on a low-budget underwater lake surveying project using a FIFISH V-EVO ROV, and I’m trying to figure out the best practical architecture for large-area coverage.
My original goal was underwater 3D reconstruction / photogrammetry of entire lakes, but after researching more, I realized the real challenge is not just imaging, it’s trajectory consistency and localization underwater where GPS doesn’t work.
Current idea:
- Use the FIFISH V-EVO mainly as a stable sensing platform
- Add an external IoT payload with:
- pH
- temperature
- turbidity
- TDS
- dissolved oxygen
- ORP
- depth sensor
- IMU
- Create environmental + bathymetric maps instead of full photorealistic reconstruction initially
Main problems I’m facing:
- How to generate repeatable survey paths over large lakes?
- How to semi-automate the survey process with a FIFISH V-EVO (which doesn’t seem to support waypoint missions)?
- How accurate would a surface GPS float/buoy system be?
One idea I had:
- Attach a floating buoy above the ROV using a short tether/rod
- Put GPS + telemetry on the float
- Use the float trajectory as approximate underwater positioning
- Possibly combine this with depth + IMU data
Questions:
- Has anyone here attempted large-area lake surveying with a tethered consumer ROV?
- Is surface-GPS-assisted surveying a reasonable approach?
- Would an autonomous surface boat towing/guiding the ROV make more sense?
- Any recommendations for low-cost bathymetry methods?
- Has anyone used RealityCapture / RealityScan / Gaussian Splatting underwater?
- Would stereo cameras help underwater in low-visibility lakes, or is sonar the only realistic route long term?
- Any advice for maintaining repeatable grid/lawnmower survey paths underwater?
Budget for the additional system is around ₹30k INR (~$350 USD), so professional USBL/DVL systems are unfortunately out of reach.
I’d really appreciate practical engineering advice from people who’ve actually worked with ROVs, hydrography, photogrammetry, or environmental surveying.
Thanks!