In 1974, in the middle of the OPEC oil shock, Edinburgh University professor Stephen Salter published a paper in Nature describing a cam-shaped floating device that would rock on incoming ocean waves, pumping hydraulic fluid through a generator. He called it the Nodding Duck. The world called it the Salter Duck.

The physics were extraordinary. A Duck sits with its rounded "back" facing the incoming waves. The wave rolls the Duck up and back; the Duck's cam profile is shaped so the far side barely moves — nearly all the wave's energy goes into rotation rather than transmitting past the device. In wave tanks at Edinburgh, prototype Ducks absorbed over 90% of incident wave energy across a broad frequency range. For comparison, a modern wind turbine's Betz limit is 59.3%. Nothing else in renewable energy comes close.

The UK Department of Energy funded the Wave Energy Programme from 1974 to 1982, spending about £15 million exploring Ducks, Cockerell rafts, and oscillating water columns. A commercial-scale Duck string — 300-meter spines carrying multiple Ducks, moored 15 km off the Hebrides — was projected to deliver baseload-scale power from the North Atlantic, where wave energy density averages 40-70 kW per meter of wave crest.

Then in 1982, the UK Atomic Energy Authority (UKAEA) — which had a direct institutional interest in nuclear winning the low-carbon race — delivered the assessment that killed the program. It calculated Duck electricity at roughly £0.46/kWh, making it uncompetitive with anything.

Salter spent the next decade proving the report was wrong. Reviews in the 1990s found that the UKAEA calculation had:

• Assumed a 25% capacity factor — a third of what the Duck actually demonstrated
• Used a discount rate of 8%, punitive versus the 5% applied to nuclear
• Included full nuclear decommissioning inflation in the comparison but ignored the Duck's zero fuel cost forever
• Cited a Duck efficiency of ~50% when tank data showed >80% in real sea states

Corrected, the number came in around £0.05/kWh in 1980s money. The program was already dead. Salter wrote in 1993: "The wave programme was killed by people who had every incentive to kill it and no incentive to check their arithmetic."

Why it works now:

• Fiber-reinforced composites and closed-cell foam cores solved the "how do you build a 300m spine that survives a North Atlantic winter" problem that dogged 1980s steel designs.
• Model-predictive control running on modern edge processors can retune the Duck's damping wave-by-wave — Salter had to use fixed hydraulic settings.
• Grid-scale battery storage now smooths the natural variability that made 1980s utilities refuse to touch wave power.
• The Hebrides transmission connector (2018) means the grid finally exists to move the power to load centers.
• Offshore wind O&M infrastructure now covers the exact latitudes where Ducks perform best — the service-vessel ecosystem no longer needs building from scratch.

Salter is 88 in 2026, still at Edinburgh, still updating the Duck design. His current version uses a gyroscopic power take-off instead of hydraulics — no oil, no seals, sealed inside the hull for a 40-year service life. Nobody's funded a full-scale build.