SOLAS Chapter V — safety of navigation

SOLAS Chapter V covers safety of navigation + applies to all ships on all voyages — broader than most SOLAS chapters. It sets carriage requirements for navigational equipment, voyage planning + weather + ice + SAR co-operation duties, chart + publication carriage, ECDIS + AIS + VDR + LRIT + BNWAS + BRM familiarisation, and the Master's obligation to render assistance. Every OOW + Master should know Chapter V by regulation number. This page is the reference cross-linked to /reference elsewhere on the site.

Selected regulations at-a-glance

Reg	Subject	Application
V/4	Navigational warnings — receive + act on NAVAREA broadcasts	All ships
V/5	Meteorological services + warnings	Coastal states + ships
V/14	Ships' manning — minimum safe manning	All ships
V/15	Principles relating to bridge design + navigation aids	All ships
V/19	Carriage requirements for shipborne navigational systems	All ships (by size + type)
V/19.2.4	AIS carriage	≥300 GT (int'l), ≥500 GT (domestic), passenger
V/19.2.10	ECDIS carriage	Tankers ≥3k GT + cargo ≥10k GT + passenger ≥500 GT
V/19-1	Long-Range Identification + Tracking (LRIT)	≥300 GT (int'l)
V/20	Voyage Data Recorder (VDR)	≥3k GT + passenger
V/22	Navigation-bridge visibility	≥55 m LOA (new-build)
V/23	Pilot transfer arrangements	All ships employing pilots
V/24	Steering-gear + rudder response testing	All ships
V/25	Electrical power supply of steering + emergency lighting	All ships
V/26	Steering gear — testing before departure	All ships
V/27	Nautical charts + publications	All ships
V/28	BNWAS (Bridge Navigational Watch Alarm System)	≥150 GT (new + existing)
V/33	Master's obligation to render assistance	All ships
V/34	Voyage planning	All ships

Master's obligation to render assistance (Reg V/33)

"The master of a ship at sea which is in a position to be able to provide assistance, on receiving information from any source that persons are in distress at sea, is bound to proceed with all speed to their assistance, if possible informing them or the search + rescue service." This is the international Good Samaritan clause. Master documents the request + decision + arrival time. Only excusable when the ship itself is unable (in casualty, in danger, or with clear justification such as ISPS security-level 3 state). Failure to render assistance is prosecuted in some jurisdictions.

BNWAS — Bridge Navigational Watch Alarm

Regulation V/28 mandates BNWAS on all cargo ships > 150 GT + passenger ships regardless of size (built or existing). The system monitors bridge activity + sounds a pre-alarm to the OOW if no activity is detected within 3-12 minutes; if no response, alarm the master + then bridge-team back-up. Reduces fatigue-driven bridge accidents. Type-approved instrument required.

Practical implications for OOW

Voyage plan reviewed + signed BEFORE departure. Not later. PSC inspects.
Steering-gear test within 12 hours before departure per Reg V/26. Recorded in the deck log.
AIS on continuously per Reg V/19.2.4.5. If Master orders off for safety/security, document the decision + duration.
ECDIS type-specific certificate held for the ECDIS on board — verify PSC + auditor may check.
VDR functional test at annual survey. Post-incident: preserve immediately.
BNWAS active on watches at sea. Documented + tested per SMS.

Frequently asked

What equipment is mandatory on all ships regardless of size?

Reg V/19.2.1 requires a standard magnetic compass, gyro compass, means to display compass reading at each helm/control station, radar reflector or SART for smaller vessels, and 121.5 MHz + 156.8 MHz VHF communications for coastal navigation. Reg V/19.2.4 adds echo sounder, speed + distance log, rate of turn indicator (for ships >50,000 GT). Every ship above 300 GT on international voyages has AIS Class A.

When is ECDIS mandatory + what training does the OOW need?

Under Reg V/19.2.10, ECDIS became mandatory on new-build tankers > 3,000 GT (2012), new-build passenger ships > 500 GT (2012), new-build cargo ships > 10,000 GT (2013), existing tankers > 3,000 GT (2015), and existing cargo ships > 10,000 GT (2018). Every OOW must hold type-specific ECDIS training for the ECDIS installed on the vessel (STCW Reg II/1). Generic ECDIS familiarisation is NOT sufficient. Paperless navigation requires TWO independent ECDIS systems; single ECDIS still requires paper-chart backup covering the intended voyage.

What is the difference between AIS Class A and Class B?

AIS Class A is mandatory on ships > 300 GT on international voyages (Reg V/19.2.4), > 500 GT on domestic voyages, and passenger ships regardless of size. Class A transmits every 2-10 seconds at 12.5W. Class B is voluntary for smaller commercial + pleasure vessels; transmits every 30 seconds at 2W. Class A shows on ECDIS + shore station tracking; Class B shows but is a lower priority. AIS may only be switched off when the Master determines transmission would compromise safety or security (Reg V/19.2.4.5).

What is VDR retention requirement + when must it be preserved?

Voyage Data Recorder retains 12 hours of bridge audio + radar + AIS + navigational data + engine + rudder + steering + heading + speed + tank + door + hull + machinery data continuously overwritten. Under Reg V/20 + IMO Res. A.861(20), after an incident the recording must be preserved for at least 30 days — the physical replaceable memory or the Long Term Data Log module must be recovered + secured. Master preserves the VDR immediately after any incident + before overwrite. Failure to preserve is a common finding in casualty investigations.

What does Reg V/34 voyage planning actually require?

Regulation V/34 requires the voyage plan to be prepared BEFORE departure covering ALL phases: berth-to-berth, taking into account weather + tidal + current + traffic + reporting requirements + safe passage. IMO Res. A.893(21) provides the 4-stage framework: appraisal (charts + publications + weather forecast) + planning (courses + alternates + no-go areas + calling points) + execution (bridge team briefed + logs kept) + monitoring (position fixes + progress against plan). PSC inspects the voyage plan + reviews the OOW's familiarisation with it.