SVOP Marine Weather Interpretation 2

Question 1

What weather hazard is associated with a rapidly falling barometer (pressure drop of 4–6 hPa or more in 3 hours)?

Accepted Answer

An approaching storm or strong wind system — operators should seek shelter or prepare for deteriorating conditions

Answer

A rapid pressure drop indicates a quickly deepening low-pressure system approaching with associated strong winds, rain, and rough seas. A drop of 4–6 hPa in 3 hours (a 'vigorous deepening') warrants immediate action.

Question 2

What is a 'thermal wind' or 'sea breeze' and when does it typically occur?

Accepted Answer

A local daytime wind blowing from sea toward land as land heats faster than water, typically peaking in the afternoon

Answer

The sea breeze develops when land heats faster than the adjacent sea during the day, warming the air above the land which rises, drawing cooler marine air inland. It typically begins mid-morning and peaks in the afternoon, creating localised onshore winds of 10–20 knots.

Question 3

What is the Beaufort Scale used for, and what does Beaufort Force 6 describe?

Accepted Answer

It describes wind speed by observable sea and wave conditions — Force 6 is 'strong breeze' with 22–27 knots and waves of 2–3 metres with white foam streaks

Answer

The Beaufort Scale relates wind speed to observable sea conditions. Force 6 ('Strong Breeze') corresponds to 22–27 knots (25–31 mph) with wave heights of 2–3 metres, white foam crests becoming more extensive, and possibly some spray.

Question 4

What is 'orographic enhancement' of rainfall and why is it important for Pacific coast vessel operators?

Accepted Answer

When moisture-laden air is forced upward by coastal mountains, producing intense localised rainfall and poor visibility on the windward slopes

Answer

Orographic (mountain-forced) enhancement causes significant rainfall and low cloud on the windward side of coastal mountains. On BC's coast, this creates highly variable conditions — clear on the leeward side but heavy rain, low cloud, and reduced visibility on windward slopes and channels.

Question 5

What weather information should a vessel operator check before departing on a coastal voyage?

Accepted Answer

Environment Canada's marine weather forecast for the specific zone, wind and sea state forecast, fog advisories, and Windspeed warnings broadcast on VHF WX channels

Answer

Operators must check the Environment Canada marine zone forecast (specific to the coastal or inland waters being used), wind/wave/visibility/swell forecasts, any special marine warnings, and extended outlooks for the voyage duration before departure.

SVOP - Small Vessel Operator Proficiency Practice Test

SVOP - Small Vessel Operator Proficiency Practice Test

SVOP Marine Weather Interpretation 2