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What Isometric's DOCS
methodology requires —
and what it doesn't.

TopicMRV and methodology
Published18 October 2026
Reading time7 minutes

DOCS v1.0 is the first community-level protocol for quantifying net removal from direct ocean capture. It is rigorous about models and monitoring, and deliberately silent about marketing.

In October 2025, Isometric published version 1.0 of its protocol for Direct Ocean Capture and Storage (DOCS). It matters for anyone buying or financing ocean-based carbon removal, because it turns a scientific argument into a set of auditable requirements. It also matters for what it leaves out.

What the protocol is for

DOCS quantifies the net carbon dioxide equivalent removed from the atmosphere by a direct ocean capture project, and the conditions under which that removal can be credited. The captured CO₂ must be delivered to durable storage — on a time scale of more than 1,000 years — and the CO₂-depleted seawater must be returned to the ocean in a condition that allows air–sea exchange to bring the surface ocean back into equilibrium.

Two reservoirs, one credit

The protocol separates two things that are easy to conflate:

  • Geological storage. The CO₂ extracted from seawater is compressed and stored in a stable reservoir.
  • Ocean uptake. The returned, CO₂-depleted seawater re-absorbs CO₂ from the atmosphere through air–sea exchange.

Credits are issued against the second — the net atmospheric removal — while permanent storage in the first is a precondition for the project to count as net negative at all. A project that captures CO₂ but cannot store it durably does not qualify, however good its ocean chemistry looks.

Why models, not measurements

Direct observation of the air–sea flux at the scale and over the time horizon that matters is impractical. The protocol therefore quantifies net removal with a validated ocean biogeochemical model, run for both the project scenario and a baseline scenario. The model requirements are set out in a separate Air–Sea CO₂ Uptake Module (v1.1). This is a deliberate design choice: the credibility of a DOCS project rests on model validation and monitoring data, not on a single measurement campaign.

Four domains

The protocol requires the project to characterise four spatial domains, because the fate of the depleted water differs across them:

  • the facility itself;
  • the mixing zone, where discharge dilutes;
  • the near-field, where tides, coastal currents and waves move the water;
  • the far-field, where regional and basin-scale processes take over.

Each domain has its own characterisation requirements. A project that models only the outfall, or only the open ocean, will not satisfy the protocol.

The baseline problem

The most difficult requirement is also the most honest: the ocean baseline is not stable. It is changing with climate change, and the protocol acknowledges that a measured “current” baseline is a moving target. Projects must model a baseline scenario, not simply compare against a historical snapshot. This is where a large share of the scientific and cost burden sits.

Monitoring and stop conditions

A monitoring plan must be prepared before the project starts and described in the project design document (PDD). It must specify duration, frequency, locations, sampling and analytical methods, and the thresholds that trigger action. The protocol expects projects to be able to detect adverse effects and, where necessary, stop. Monitoring is not a formality appended to the end of the PDD; it is part of the project's operating conditions.

Reversal and buffers

Storage carries reversal risk. Each storage reservoir must have its own buffer pool, separate from the project's other reservoirs; the protocol gives the example of a 2% buffer for a saline aquifer. The buffer is a financial and accounting mechanism, not a substitute for site characterisation.

The standards stack

DOCS sits on ISO 14064-2:2019 for project-level quantification, ISO 14064-3:2019 for verification, and ISO 14040/14044 for life-cycle assessment. Verification is performed by an accredited validation and verification body (VVB), and the protocol anticipates that Isometric may also engage an independent third party. Projects are also expected to share scientific data, subject to confidentiality protections.

What it does not do

DOCS v1.0 is a methodology, not a certificate. Specifically, it does not:

  • register a project or write its PDD;
  • appoint a VVB or issue credits;
  • replace environmental permits, EIA, sea-use approval or land allocation;
  • validate a company's public claims about certification;
  • guarantee that buyers will pay a given price.

That distinction matters commercially. “Designed against DOCS” and “certified under DOCS” are different statements, and only one of them can be made before a project is registered and verified.

Five questions a buyer should ask

  1. Is the project registered, and is there a PDD?
  2. Which VVB is engaged, and what is its accreditation?
  3. Which ocean model was used, and how was it validated against observations?
  4. What are the monitoring thresholds and stop conditions?
  5. What buffer applies to the storage reservoir, and who bears reversal risk?

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