Where candidates go wrong
Most candidates can recite the four stages of voyage planning — appraisal, planning, execution, monitoring — but when pressed on restricted waters specifically, answers become vague. Examiners want to hear that you have actively anticipated the constraints of the passage, not merely drawn a line on a chart. The failure is treating restricted waters as just 'careful navigation' rather than a structured, pre-departure decision-making process.
Statutory and regulatory framework
The duty to plan passages is imposed by SOLAS Chapter V Regulation 34 — this is the highest authority and the answer an examiner expects at command standard. The four-stage framework of appraisal, planning, execution, and monitoring derives from IMO Resolution A.893(21) Guidelines for Voyage Planning, which fleshes out how that statutory duty is discharged. MCA guidance note MGN 315 amplifies the requirement for UK vessels and provides practical direction consistent with both instruments. When answering an examiner, anchor first to SOLAS V/34, then reference A.893(21) as the source of the four-stage structure.
The four-stage framework applied to restricted waters
Appraisal is where thorough preparation begins. For restricted waters this means:
- Correcting all charts and publications to the latest Notices to Mariners; identify whether electronic charts (ENC or RNC) are the most recent issue
- Gathering tidal data: times, heights, and critically tidal streams — direction and rate at each hour of the passage
- Identifying the controlling depth and confirming your vessel's draught plus adequate UKC (establish the company/master's minimum UKC policy and apply it)
- Noting all TSS, VTS, and compulsory pilotage limits; confirming whether a pilot is legally required or operationally prudent
- Weather windows: restricted waters amplify the effect of wind-against-tide sea state and reduced visibility
- Identifying ports of refuge and abort positions along the route
Planning turns appraisal into a formal, written plan:
- Lay off waypoints with clearing bearings and clearing ranges from hazards, not just a centre-line track
- Calculate the latest departure time that guarantees sufficient water over shoals or under bridges at the critical point — work backwards from tidal window
- Set no-go areas on the chart or ECDIS; programme safety contour and safety depth
- Identify radar conspicuous marks and leading lines for each critical section
- Pre-determine contingency actions: if a drag, equipment failure, or loss of visibility occurs at each critical waypoint, what is the action?
- Brief the crew; assign roles for the approach
Execution requires adherence to the plan with a commanded, not passive, conning style:
- Cross-track error tolerance must be narrower in restricted waters; monitor it actively
- Appoint a dedicated lookout; helm on manual
- Maintain the planned communication watches (VHF, VTS)
Monitoring closes the loop:
- Continuously compare actual position, speed, and tidal effect against the planned timeline
- If behind schedule, the tidal window may be lost — know your abort criteria in advance and act on them without hesitation
UKC and tidal windows — the examiner's favourite pressure point
You must be able to state your UKC policy numerically, justify it, and explain how tidal predictions are applied to it. Quoting 'sufficient' is not acceptable at command standard.