Overview
ISO 22822:2023 - Large yachts - Quality assessment and acceptance criteria - Dynamic positioning on large yachts specifies minimum requirements and assessment methods for dynamic positioning (DP) systems on large recreational yachts. The standard defines required equipment (power system, thrusters, DP control system, position/heading and wind sensors), a calculation method to quantify DP stationkeeping capability, and guidance on testing, trials and personnel/operational requirements. It applies to recreational DP use: short-duration operations in mild weather, not mission‑critical tasks.
Key topics and technical requirements
- Scope and application
- Targets DP systems on large yachts intended for recreational use (hours-long use, mild weather).
- Not a replacement for commercial DP class notations (IMO/ classification society schemes).
- Minimum equipment requirements
- Power system - prime movers/generators/switchboards or diesel-electric arrangements to supply thrusters and on-board systems.
- Thrusters - configuration must provide independent longitudinal (Fx), transverse (Fy) forces and yawing moment (Mxy); azimuthing and electric thrusters are preferred for responsiveness.
- DP control system - state estimator, controller (e.g. PID), and thrust allocation algorithm to compute and distribute required forces.
- Sensors - at least one position reference (e.g. GPS), one heading sensor (compass), and one wind speed/direction sensor.
- DP stationkeeping capability
- Three-step calculation method:
- Thruster configuration analysis (confirm capability to produce Fx, Fy and M).
- Static DP capability plots (polar plots showing maximum wind speed per wind direction).
- Optional advanced/time‑domain analysis for dynamic performance, fuel use, noise/vibration.
- Testing, trials and personnel
- Guidance on commissioning tests and trials to validate capability plots and equipment performance.
- Personnel requirements explained; while yacht DP systems typically do not require the redundancy or specialized crewing of commercial DP classes, the role of a DP operator (DPO) and standardized DPO training/certification are described.
Practical applications - who uses ISO 22822:2023
- Yacht designers and naval architects assessing DP feasibility and sizing thrusters/power systems.
- Equipment manufacturers and system integrators specifying DP control systems, thrusters and sensors.
- Yacht builders and owners validating stationkeeping capability, commissioning trials and operational procedures.
- Surveyors and classification/flag authorities seeking a consistent acceptance criterion for recreational DP installations.
Related standards and references
- Aligns conceptually with IMO equipment class definitions (Class 1/2/3) and MSC.1/Circ.1580 terminology, while focusing on recreational yacht application.
- ISO 22822:2023 contains no normative references but provides informative annexes describing thruster configurations and DP capability plots to support implementation.
Keywords: ISO 22822:2023, dynamic positioning, DP systems, large yachts, DP capability plots, thrusters, DP control system, stationkeeping capability, DP operator.
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