Overview
ISO 11547:1994 - Small craft: Start-in-gear protection - is an international safety standard that specifies requirements to prevent an outboard motor from being started while in gear on small craft (hull length up to 24 m). First published in 1994 by ISO/TC 188 (Pleasure craft), the standard targets outboard propulsion systems where inadvertent starting in gear could produce dangerous thrust or sudden vessel movement.
Key topics and technical requirements
- Scope: Applies to outboard motors installed on small craft up to 24 m length of hull.
- Static thrust threshold: Any outboard with a static thrust (measured per ISO 13342) of 500 N or greater must have a start-in-gear protection device.
- Protection location: The protective device may be:
- Integrated into the motor’s local starter system, or
- Integrated into the remote control/starting system.
- Definitions provided: important terms such as static thrust, remote control, remote starting, and local starting are defined to ensure consistent interpretation.
- Labeling:
- Products must carry an information label visible to the person operating the manual start control.
- If protection is in the remote system, an additional label near the motor connection must show the ISO 11192 symbols for warning and read the user manual.
- User documentation:
- If a motor that should have a protection device is not equipped with one, the user manual must state that the controls should be equipped with such a device.
- For motors normally started remotely but that also permit local starting (where the local controls are not easily accessible), the user manual must explain correct system use.
Practical applications and users
ISO 11547 is practical for:
- Outboard motor manufacturers - to design compliant starters and incorporate required interlocks.
- Boat builders and marine OEMs - for safe installation and system integration on small craft (≤24 m).
- Marina operators, installers and service technicians - to verify correct labeling and functional protection during commissioning and maintenance.
- Regulatory and conformity assessors - to audit compliance, safety labeling and user manual content.
- Safety engineers - to mitigate risks of accidental vessel movement or injury caused by starting an engine while in gear.
Adhering to ISO 11547 helps reduce accidental starts in gear, improves operator awareness via labeling and manuals, and supports regulatory compliance for small craft propulsion safety.
Related standards
- ISO 13342 - Measurement of static thrust for outboard motors (referenced for the 500 N threshold).
- ISO 11192 - Graphical symbols - used for warning and “read manual” symbols on labels.
