ISO 11591:2020

Overview

ISO 11591:2020 - Small craft: Field of vision from the steering position specifies visibility requirements for small craft up to 24 m length of hull (LH) in accordance with ISO 8666:2016. It defines how much of the forward, vertical and astern environment must be visible from the designated steering position(s), sets eye‑position references, and requires information and warnings in the owner’s manual for conditions that can limit vision.

Key topics and technical requirements

• Horizontal forward field of vision: a minimum arc of 112.5° to starboard and 112.5° to port (total minimum 225°) from the steering eye position, achievable without leaving the steering position.
• Vertical field of vision: forward vision must include the horizon and water surface based on the craft’s loaded level reference.
• Obstructed vertical vision distance: the vertical obstruction distance to the water surface (measured from the point of visual obstruction) shall not exceed 4 × length of hull (L) and in no case exceed 50 m.
• Astern visibility: where permanent obstructions exist, astern visibility must be provided by operator movement, mirrors, or other means so the operator can maintain control.
• Eye‑position definitions: high/low eye positions for standing and seated operators are specified (e.g., standing high 1 730 mm, low 1 480 mm; seated high 840 mm, low 690 mm, each 400 mm from steering wheel center).
• Main steering position: at least one steering position must meet the standard and be designated the main steering position; non‑complying positions must display standard warning symbols and text.
• Special craft requirements: additional clauses cover human‑powered craft (ability to turn to look), power‑driven craft (vertical field extending ±15° forward and seat height adjustment options), and sailing craft (sails may be transparent to comply; steering means).
• Owner’s manual: per ISO 10240:2019, manuals must list vision‑limiting factors (loading, speed, trim, sea conditions, reduced visibility, movable gear, etc.) and include specified warning labels.

Applications and who uses it

ISO 11591:2020 is used by:

• Naval architects and small craft designers to ensure compliant helm layouts and superstructure geometry.
• Boat builders and manufacturers to verify visibility during design reviews and production.
• Safety officers, certification bodies and surveyors for compliance and inspections.
• Owner/operators and fleets to understand limitations, required warnings and safe steering practices.
• Regulators and standardization bodies referencing visibility requirements in national rules.

Keywords: ISO 11591:2020, field of vision, small craft, steering position, visibility requirements, owner’s manual, ISO 8666.

Related standards

• ISO 8666:2016 - Small craft - Principal data
• ISO 10240:2019 - Small craft - Owner’s manual
• ISO 7010:2019 and ISO 11192:2005 - Required safety symbols and warning signage