The C750D Power Upgrade
Underwater, every watt has a cost. It shows up as a shorter ROV dive, a tighter power budget on an uncrewed platform, or one more battery swap on a station that is supposed to run untouched for months. With the new C750D, we set out to take that cost down — and keep the picture exactly as sharp.
Power is the real limit on the water
Imaging sonar earns its place by what it shows, but it lives or dies by what it draws. On small AUVs, micro-ROVs and surface uncrewed vessels, the sonar competes directly with thrust and runtime for a fixed energy budget. On long-term monitoring deployments — aquaculture platforms, quay-side observation, cooling-water intake watch — consumption sets how often a crew has to go out, recover hardware and swap an energy pack. Cutting draw is not a spec-sheet flourish; it is more mission time and lower cost of ownership.
Re-engineered from the circuit up
The new C750D replaces the previous generation's high-draw analog stage with a fully digital design: an upgraded low-noise, high-density acoustic channel and a smart dynamic power-management algorithm that schedules consumption to the work actually being done. The result is a typical whole-unit draw under 25 W, a steep drop from the earlier C750D-III — with no change to how the system images.
The drop, frequency by frequency
The charts below are measured power draw across range, comparing the new C750D against the previous-generation C750D-III. In low-frequency mode (750 kHz), the C750D stays consistently below the older unit from 1 m out to its full 120 m reach — up to ~56% lower at close range, where most working time is spent. The gap narrows toward maximum range, as expected, but the C750D never crosses above the previous generation.
In high-frequency mode (1.2 MHz), the pattern holds: a ~40% reduction at short range, tapering to roughly 15% at maximum range. The C750D consistently uses less energy while delivering identical imaging.
How the savings were found
The engineering team focused on three levers. First, the analog transmit/receive chain was replaced with a digital transceiver that draws less quiescent current and can throttle on a per-ping basis. Second, a new DSP schedules acoustic activity to match the configured update rate, so the system sleeps between pings rather than idling at full draw. Third, the power rail was re-architected to eliminate step-down losses from the previous linear regulator stage, replacing it with a high-efficiency switched-mode supply. None of these changes touch the acoustic beam count, the beam width or the imaging algorithm — the picture stays exactly the same.
More time on station, fewer battery swaps
For a typical monitoring deployment running 24/7 on a sealed battery pack, the ~50% power reduction translates directly into mission duration. A station that previously needed a service visit every four months can now run for six or more before a swap is due. On mobile platforms — ROVs, AUVs, USVs — the savings free up energy budget for propulsion or additional sensors without sacrificing imaging coverage.