# EXO-01 validation protocol — phase 1

**BIUTOPIC SAS — version 2.0, 30 August 2026**
Open methodological document. Reusable and citable.

---

## Purpose

EXO-01 is a self-floating electric vessel — it navigates on its own — designed to
then couple to another vessel with lines, forming a combined working unit. This
protocol defines how the platform is validated **before** any environmental
measurement campaign.

The principle is simple: until the platform is qualified, any data produced with it
is arguable. Phase 1 therefore produces no science; it produces the engineering
figures that will make the science defensible.

## What this protocol does not cover

Decisional autonomy. EXO-01 is not an autonomous craft in the robotics sense and is
not intended to become one: an operator is present at all times. No autonomous
navigation metric appears here.

## Two stages

Validation happens in two stages, in this order, without overlap.

### Stage A — EXO-01 as a vessel

| Ref. | Criterion | Measurement |
|---|---|---|
| A1 | Flotation | draught, trim, freeboard, behaviour under load |
| A2 | Propulsion | speed/power curve at four throttle settings, run out and back to cancel the current |
| A3 | Energy | daily solar yield, cruise consumption, endurance, end-of-mission state-of-charge margin — repeated under clear and overcast skies |
| A4 | Handling | turning circle, stopping distance from cruise speed, behaviour in wind and current |
| A5 | Safety | emergency stop verified every outing, watertightness, fixings, temperatures |
| A6 | Framework | vessel insurance and registration |

**Condition for entering stage B:** A1 and A5 achieved, and A2, A3, A4 reproducible
across at least three outings.

### Stage B — the coupled unit

Coupling is done **with lines**, a deliberate choice: two vessels moored alongside
remain two vessels, which avoids creating a composite unit falling under a separate
regulatory regime.

| Ref. | Criterion | Measurement |
|---|---|---|
| B1 | Coupling | approach manoeuvre, duration, crew required, absence of any modification to the coupled vessel |
| B2 | Separation | duration under normal conditions, **and a timed emergency separation**, with explicit designation of who gives the order |
| B3 | Operating envelope | maximum wind, current and chop beyond which the manoeuvre is no longer safe |
| B4 | Performance | speed/power, turning circle, stopping distance — **measured again and compared against the solo values** |
| B4bis | Course-holding | propulsion being offset to one side, the unit tends to turn; ability to hold a heading and the correction required |
| B5 | Interface under load | relative movement between hulls, steadiness of line tension, chafe, **maximum speed judged safe for the pair** |
| B6 | Envelope | characteristics of coupleable vessels: length, beam, freeboard, displacement, mooring points |

## Three methodological points that determine validity

**1. Every performance figure exists twice.** A coupled unit has neither the drag, nor
the stability, nor the turning circle of the vessel alone. Publishing a single value
per criterion would be a methodological error: the tables systematically compare solo
and coupled, and the difference is the result.

**2. Course-holding is tested before anything else in stage B.** Propulsion offset to
one side creates a turning moment. If the unit cannot hold a heading without constant
correction, speed and endurance measurements have no object.

**3. Exit criteria are thresholds, not durations.** The phase ends when values are
reproducible, not on a date. An announced duration is an estimate; a threshold reached
is a result.

## Recording

One sheet per outing, completed on site: meteorological and hydrological conditions,
measurements by criterion, and a **classified failure log** (mechanical, electrical,
energy, mooring, operator) stating for each anomaly how it was recovered and the
downtime incurred. Days without an outing are recorded too: a blocker is only visible
if the absence of progress is written down.

## Safety

An operator is present at all times. The emergency stop is verified before every
outing, without exception. In stage B, the emergency separation plan is briefed to the
crew before coupling.

---

*This protocol is published openly so that it can be discussed, reused and criticised.
Datasets produced under it will be published separately.
Contact: hydronaute@biutopic.com*