May 28, 2026 · 49m · catalyst
Building inference data centers on the high seas
0:00 / 0:00
gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
In this episode of Catalyst, host Shayle Kann speaks with Panthalassa CEO Garth Sheldon-Coulson about deploying untethered, wave-powered floating data centers in the deep ocean, exploring the hydrokinetic engineering, cooling economics, and satellite connectivity tailored for AI inference workloads.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. Shayle holds 21.3% of the talking time here. How this is scored →
Shayle as informed peer 5.8 Guest teaching 4.6 Guest disagreement 1.1 Shayle pushing back 2.8
speaking balance: gold is Shayle, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 24:59 Guest defends ultra-low power cost claims
Garth firmly counters the suggestion that offshore power cannot be the cheapest by asserting they have two-cent per kilowatt-hour designs and achieve over ninety percent capacity factor.
Hardest push from Shayle ▶ 30:33 Host refuses broad footprint comparisonShayle immediately halts Garth's claim that their system has one-hundredth the global land footprint of other energy sources by pointing out that natural gas has vastly higher energy density.
Biggest teaching moment ▶ 16:20 Explaining why wave energy avoids coastal degradationGarth details how open-ocean swells capture compounding wind energy losslessly across thousands of miles, educating the host on why coastal wave generators historically starved for energy.
Shayle holds their own ▶ 32:21 Host drills on power electronics and inverter failure ratesShayle challenges the assumption of maintenance-free operation by citing real-world terrestrial solar inverter and generator failure rates to question open-ocean marine durability.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | Shayle as informed peer | Guest teaching | Guest disagreement | Shayle pushing back | Why |
|---|---|---|---|---|---|---|
| How the Panthalassa Node and Ocean Hydro Generation Work | 6 | 4 | 1 | 4 | Shayle probes into the mechanics of the self-propulsion and closed-loop hydro generation, pressing on the apparent chicken-and-egg problem of low near-shore wave resources. Garth explains the hydrodynamic hull shaping and towing strategy to address the logistical constraint. | |
| Physical Scale and Differences from Historical Wave Energy | 5 | 5 | 1 | 2 | Shayle contextualizes the physical size against offshore oil rigs and asks what fundamentally separates Panthalassa from failed historical wave energy attempts. Garth details the choice to go untethered into the open ocean rather than staying in coastal shallows. | |
| The Ocean Wave Energy Resource and Battery Dynamics | 5 | 6 | 1 | 2 | Garth details the wave resource consistency in the southern hemisphere, framing it as the world's largest solar battery. Shayle accurately infers the battery integration requirements and operational capacity implications under seasonal swell variations. | |
| Capital Expenditure, Power Costs, and Data Center Economics | 7 | 4 | 2 | 3 | Shayle highlights CapEx drivers like onboard battery costs, comparing them to overall hardware costs. Garth explains why compute economics shifted their design philosophy away from ultra-cheap power toward maximum uptime, reliability, and free convective seawater cooling. | |
| Sponsor Segment: Fast and Flexible Power Deployments | 6 | 4 | 2 | 5 | Following the mid-episode sponsor reads, Shayle challenges the scale disparity of a massive node powering just one hyperscale rack and pushes back against land footprint comparisons regarding natural gas. Shayle also questions open-ocean electrical and inverter maintenance vulnerabilities. | |
| Server Reliability and Environmental Advantages at Sea | 6 | 5 | 1 | 3 | Shayle pushes into the operational logistics and downtime costs of retrieving malfunctioning servers. Garth outlines empirical GPU failure modeling and argues that cold water temperatures and nitrogen-sealed, oxygen-free enclosures will reduce failure rates below terrestrial benchmarks. | |
| Market Workloads, AI Inference, and Satellite Connectivity | 6 | 5 | 1 | 2 | Shayle identifies latency tolerance and node networking constraints as core product parameters. Garth explains why long-running agentic inference and reinforcement learning do not require massive localized networking or millisecond latency. | |
| Prototype History, the Ocean 3 Pilot, and Commercial Roadmap | 5 | 4 | 0 | 1 | Shayle asks for a concrete roadmap of deployments, clarifying what 'full scale' entails. Garth outlines the progression from North Pacific test rigs to Ocean 3 commercial manufacturing and southern hemisphere deployments. |
Statements from this episode (18)
Panthalassa nodes passively self-propel continuously using wave heave against their hulls
“We have the pumping action into the reservoir. We also have a shape towards the bottom of the system that pushes water backwards, so the system moves forward. The system is always moving forward. It's always moving forward as it moves up and down. And so all w…”
Panthalassa plans factories near high-energy seas to minimize node towing distances
“We want to put them in the regions, near the regions where the energy is the best, and in the locations where we want to put them, you can absolutely just tow them 50 miles offshore, flip them, and then they can work their way out into the resource under their…”
Sheldon-Coulson: Panthalassa nodes span 10-30 meters wide and 70-100 meters deep
“A node is anywhere from 10 meters across at the top, like our Ocean Two that we did two years ago, and Ocean Three is about that as well but up to 30 meters across at the top. And you sort of get diminishing returns after about 25 or 30 meters, and then it goe…”
A 15-meter Panthalassa floating node receives over 2 MW of wave energy
“If you put an object that's, say, like, 15 meters across in this region, you can calculate how much energy is fluxing through you in the form of the waves, and it amounts to, like, well over a megawatt. You know, it's two two and a half megawatts on average in…”
Panthalassa wave data centers achieve 99.8 percent availability with minimal batteries
“In all of our optimizations, we can be achieving for payloads, you know, we can be achieving with very little battery, like, 99.5, 99.8% power availability with far less battery than you would need for an equivalent solar installation, for example.”
Sheldon-Coulson: Panthalassa node CapEx is half steel, one-quarter powertrain
“In a system where if we just exclude the battery for the minute it's most, it's basically half steel, and then you've got about a quarter is your powertrain. And then about a little less than a quarter is your marine coatings, and then you've got other, you kn…”
Panthalassa manufactures its own turbines, generators, and power electronics
“So we have all of that stack in-house. It's a pretty short stack. You know, we make the turbines ourselves, we make the generators ourselves, and we make the power electronics ourselves, and then you have something that you can integrate a payload directly int…”
Floating wave nodes represent only 10 to 20 percent of total costs
“If you're doing computing, it can easily be the case that the node is, the node itself is like a fifth to a 10th of the cost structure, especially if you count multiple replacements of the payload over time.”
Panthalassa designs deliver wave power at 3.5 to 4 cents per kWh
“We have designs that are two cent per kilowatt hour, On the power. And we, the optimum tends to be, you know, given everything I was just describing, the optimum tends to be in the four cent, three and a half to four cent per kilowatt hour range. But keep in m…”
Ocean convective cooling eliminates traditional data center cooling infrastructure costs for Panthalassa
“We are actually in a resource that gives us free, extremely good convective cooling, and that's huge, because it essentially lets you eliminate the entire cost structure of the data center. And our object is actually replacing both power plant and data center,…”
Sheldon-Coulson: Panthalassa ocean nodes have 200kW to 1MW capacity
“An individual node is on the order of 200 kilowatts up to a megawatt, depending on design, size optimizations, and so forth. We think that the economic optimum for most applications will end up being in the 400 kilowatt range”
Panthalassa power supplies use purely analog logic without firmware or liquid capacitors
“It's all, ah, analog logic that runs our power supplies. There's no firmware, ah, no capacitors with liquids inside that can evaporate.”
Sheldon-Coulson predicts AI hardware will shift away from failure-prone high-bandwidth memory
“There's lots of new accelerators that don't use as much high bandwidth memory and other components that are particularly failure prone, and that's where a lot of the industry will be going.”
Panthalassa expects lower AI chip failure rates at sea than on land
“In many cases, we believe that the reliability of the chips, the failure rates will actually be lower on our platform because we can provide much colder cooling temperatures than is typical on land, and we have no oxygen. We eliminate the oxygen from the paylo…”
Sheldon-Coulson: Panthalassa satellite connection adds 100 milliseconds of latency
“The additional latency that we have is only like a hundred milliseconds. That, Vanishes into the, even the latency of time to first token on most pre-fill certainly on the interactive latency of a human waiting for an output”
Bulk of AI energy consumption will power long-running background processes
“There's a whole class of like super latency sensitive applications where you wouldn't want to use us. But that's not where the bulk of energy will be going. The bulk of energy will be going to very long running processes that are churning, churning, churning t…”
AI reinforcement learning energy demand probably already exceeds traditional pre-training
“And this is an area that is becoming huge in terms of energy demand. It'll, it will, The probably already is bigger than what we have historically considered training, you know, pre-training”
Panthalassa: Prototypes proved offshore compute, hydrogen production, and propulsion
“We've put a series of full-scale prototypes in the water. So Ocean One which was back in 2019 no, sorry, 2021. Ocean Two, which was 2024, Wave Hopper, which was also 2024. So a series of prototypes that have proven Computing, hydrogen production, propulsion op…”