Speed limits are posted in kph on round white signs ringed in red. "No Wake" signs are similar, with a blue wavy line inside a red ring. Speeds are posted in kilometres per hour, which is roughly double the number of knots. Even if they are not posted near marinas, narrow sections, in canals, and along sensitive shorelines, you should operate at a "no-wake" speed. (Speed conversion chart)
You are responsible to operate your boat in a safe manner and prevent damage caused by your wake or wash, even if no signs are posted. If your boat or its wake damages property or injures people, you may have broken the law in many jurisdictions (Canada Shipping Act, Maritime Law, provincial laws). The person who suffers damage must be able to identify the boat and the operator and prove it caused the damage (witnesses are helpful). (Boating Laws: Contraventions Act)
There is a general non-posted 10 kph speed limit within 30 metres (100') from shore in the waters of Ontario, Manitoba, Saskatchewan and Alberta, rivers and lakes in British Columbia and Nova Scotia. This limit does not apply to rivers less than 100 metres wide. Posted speed limits less than 10 km/h limits would override the “less than 100 m wide exception”. This rule does not apply to canals or buoyed channels where different restrictions apply. Penalties are fines up to $500 or six months imprisonment. (Canada Shipping Act: Boating Restriction Regulations)
A boat pulling a skier perpendicular (directly away) from shore or within a buoyed water ski area is exempt from the "30-metre" rule. Under the Small Vessel Regulations governing water skiing, a spotter, not operating the boat, is required on board. You must have a seat for each person being towed in case recovery is necessary. Only personal watercraft (PWC's) designed to carry three people can be used for towing water skiers (driver, spotter, skier). Towing activities are not allowed in the period from one hour after sunset to sunrise.
Contact the Canadian Coast Guard 1-800-267-6687 for more information.
Every boat's wake speed range is different. Excess speed not only damages shoreline, but is hazardous to small boats and swimmers. Loons are particularly vulnerable to wakes. Slow down as you approach locks and bridges, and also while passing moored craft.
How you speed up and slow down is important. Operating your boat at less than "hull speed" (about 8 mph for a 10 metre boat), a boat makes very little wake -- the angled wave that is created by the bow and stern of the boat. As you increase speed beyond hull speed, the bow begins to rise and the wake from the bow begins to meet the wake from the stern, causing the combined wave to increase in height and volume. This applies to both planing hulls (runabout, power cruiser) and displacement hulls (trawler, sailboat), but the planing hull can continue "on step", which lifts the hull on top of the water to plane at faster speeds.
Between hull speed and planing speed, there is a speed range where the boat will throw maximum wakes and uses maximum fuel. Just before the boat begins to lift onto plane and level out, even a small boat can capsize nearby canoes or wash away shoreline.
You should have a look behind you occasionally to see how your wake affects other boats and shoreline. Wake affects increase dramatically if the boat is operating in shallow water. Near vertical breakwaters, the wave will reflects back off the vertical surface, creating even larger waves.
A recent review of 50 cases of "boat sinking while underway" by BOAT/U.S. Marine Insurance found that 30% were caused by waves over the gunwales of the boat!
Attempts by a displacement boat to exceed hull speed simply waster fuel and create large wakes. Displacement speeds are fuel-efficient for displacement hulls. Planing hulls get their best fuel economy on plane. Semi-planing hulls are built to exceed hull speed.
A message in a boating newsgroup describes it:
Semi-planing in a planing hull, although commonly seen, is just horrible, with the engine straining, the bow pointed up, and a large rolling wake which can be seen striking the shore and rolling other boats. Lots of fuel is used, with no additional forward speed!
Slow down and cross it at a slight angle. A wake will push you sideways or even capsize a small boat, so don't stop. Never take a large wake abeam, to prevent taking water over the side or having people fall overboard. Injuries from an unexpected wake can happen quickly. Yell "wake" to alert everyone to grab on or get low in a small boat. The sudden hit from falling off a wake has broken peoples' spines!
The "ICW Pass" is something we learned from an experienced east coast cruiser. Here's how it works:
The passing boat comes off plane right astern of you, which passes the boat wake harmlessly away on both sides of your boat. When YOU see this, maintain course, slow down and make "eye contact" to show you are cooperating in the ICW Pass. The passing boat will now pass you at displacement speed. As soon as the pass is complete, you both resume your former speed. All the professional delivery captains do this - heart-stopping the first time you see it, but it works well. An ICW rookie will just wake you out. (Please refrain from a one-finger salute - Canucks should always take the high road.)