Jan 29
'More than Paper Charts' – What Is The Canadian Hydrographic Service (CHS)?
- Richard Crowder
- 2 days ago
- 6 min read
Updated: 1 day ago
Unbeknownst to many, Canada has the longest coastline of any country in the world, with more than a third of our territory existing under water. Given the extent of our coastline and water coverage, the size and scope of the Canadian Hydrographic Service is truly remarkable.
As a division of the Science Branch of the Department of Fisheries and Oceans Canada (DFO), with a small fleet of survey vessels and access to ships of the Canadian Coast Guard (CCG), the Canadian Hydrographic Service has four main directives:
determining Canada's maritime zones and boundaries in support of Canada’s sovereignty
monitoring tides, currents, water levels, and essential information for detecting and predicting climate change and climate variability, as well as natural hazards
producing navigational charts and nautical publications to ensure the safe navigation of Canada's waterways
collecting high-resolution data on the depth, shape and structure of Canada's oceans, lakes and rivers
That can be summarized succinctly by saying that the Canadian Hydrographic Service specializes in the access to, the collection of, and the analysis of dynamic digital and analog data. It also requires the measurement and description of the physical, biological, and chemical features of oceans, coastal areas, lakes, and rivers from all possible sources. The end product is to spread this knowledge for navigational safety and scientific progress.
That’s all well and good, but let’s break it down into useful segments for pleasure boaters. CHS, by necessity, focuses on commercial shipping but pleasure boating benefits greatly from their work. For example, the aids to navigation throughout the Rideau and Trent-Severn Waterway systems, as well as innumerable inland lakes and waterways, are extremely popular (and necessary) for pleasure boaters.
In the three years prior to 1882, close to 500 lives had been lost on the Great Lakes. In September 1882, the steamer Asia departed Parry Sound and was lost in a hurricane on Georgian Bay. In what was Canada’s worst maritime disaster up to that time, up to 150 passengers and crew were lost, with some later washing up on Lonely Island located southeast of Manitoulin Island. Some claim the ship must have hit a submerged uncharted shoal. Regardless of cause or blame, the loss was the catalyst for government action.
The following year, the government of the Dominion of Canada legislated into action the Georgian Bay Survey to create a detailed hydrological survey and charts of the waters of Georgian Bay and Lake Huron. This legislation also authorized the construction of more lighthouses throughout Canada. At that time, lighthouses had to be manned so the kerosene flame of the light could be lit every night and the wick of the lamp trimmed to the correct length. A person was also needed to sound the appropriate fog horn when necessary. The government always preferred young married men to be the lighthouse keepers with the support and assistance in all matters from their unpaid wives.
This was a 24/7 job during the shipping season, with no time off until winter. Into the mid-1900s, lighthouses gradually became automated as electricity became more available and the cost of labour and maintenance of lighthouse residences continued to rise unabated. Cove Island Lighthouse, located in Lake Huron just north of the Bruce Peninsula, was the last remaining staffed lighthouse on the Great Lakes. It was automated in 1991.
Hydrographic surveying and charting gradually expanded to include all appropriate inland waters and coastal areas of Canada. Surveying and charting of the Pacific coast started in 1891. It was 1905 before this was extended to the Maritimes and to the Lower St. Lawrence River east of Quebec City. In the meantime, in 1893, the importance of nationwide monitoring and reporting of coastal tides and currents was recognized and acted upon. The year 1912 saw the start of precise water level gauging of the Great Lakes.
To reflect its national scope, in 1904 the Georgian Bay Survey became the Hydrographic Survey of Canada. To further reflect its expanded mandate, in 1928 it became the Canadian Hydrographic Service. The addition of Newfoundland and Labrador into Confederation in 1949 extended the geographic reach of CHS. Canada’s participation in the mid-1950s in the Distant Early Warning (DEW) radar detection system across northern Canada required CHS to chart Canada’s arctic waters and coastline to facilitate the safe shipment of construction materials with which to build the DEW sites.
The early days of hydrographic surveying were onerous and laborious in that water depth was achieved by lowering a weighted line that was marked off, usually every foot or fathom, to determine the water's depth. This line had to be lowered every few feet along the surface in order to create an outline of the bottom of a particular body of water.
The surveyors (hydrographers) also had to know where on the surface of the Earth this water depth occurred. If the survey was being done within sight of a body of land having a known location, then triangulation could be used to pinpoint the location of the depth of water just measured. If out of sight of land, then a sextant had to be used to determine the location. As you can no doubt imagine, the accuracy of early chartwork was relative to say the least.
The progressive improvements and sophistication of electronic instrumentation since the 1950s has resulted in exponentially increased accuracy of hydrography. Today, as the CHS vessel travels a precise grid system on the surface of the body of water, the depth of water is measured using sonar (echo-sounders). The position of the survey vessel is determined via the latest satellite measuring technology which is accurate to between one and three metres.
But, the depth of water in any given location on any given hour of the day in tidal water may vary -- sometimes dramatically. Therefore, a reference water level datum is chosen and published for every body of water. This reference level or datum in fresh (non-tidal) water is often chosen to be the mean water level (MWL) for that body of water. In tidal waters, it is often Mean Low Water Level (MLWL). This level is clearly marked on official nautical charts and all water depths and heights above water are calculated from this datum level. It is therefore important for you to know how far above (or below) this reference datum the body of water is on the particular day, or even time of day (in tidal water), when you are boating.
CHS then combines this water depth information with the make-up of the water bottom characteristics, geographical features, hazards to navigation, tides, currents, and aids to navigation to produce essential nautical publications. These include paper and electronic charts, annual tide and current tables, sailing directions which provide the best approaches to harbours, hourly tidal current information, catalogue of current paper charts, and Chart #1 which provides essential explanation of symbols and terms used on CHS charts.
CHS produces over 900 different paper charts. These used to be mandatory to have on board when boating on any waterway where they were available. If your vessel is over 100 tons, they are still mandatory. Stick-on updates were available for you to glue on to your chart until updated charts were printed. Now, instead of being inventoried, charts are printed “on demand” when one is ordered and contains the most up to date information. CHS has made Electronic Navigational Charts available since 2007 and may be ordered online through the CHS website. Electronic charts provide a world of practical use improvement over paper charts with backup even available on your smartphone in case your on-board chartplotter fails.
Canadian Hydrographic Service is part of the global Argo (Jason’s ship in Greek mythology) Global Ocean Observing System of 25 countries utilizing 3000 free-drifting depth-controllable floats across the open ocean. These floats provide climate research, weather forecasting, and ocean modelling information including temperature and salinity via satellite of the upper two thousand metres of global ocean.
Canada, through Canadian Hydrographic Service is a recognized world-renowned leader in several areas of ocean and inland waters surveying and data collection techniques including:
multibeam modelling technologies providing a more sophisticated and useful knowledge of the seabed
Arctic ocean surveying techniques including ice-covered waters
utilization of Autonomous Surface Vessels (ASV’s) to remotely collect data
development and implementation in emerging technologies including Maritime Autonomous Surface Ships (MASS), underwater, airborne, and micro-satellite autonomous hydrographic
vessels and hydrospatial (there’s that word again!) artificial intelligence gathering
CHS is perhaps the least obvious, but arguably the most vital, government service available to and utilized by boaters from coast to coast to coast in Canada.
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