BASIC POWERBOATING. SAFETY & RESCUE FOR SAILING INSTRUCTORS 87


TOWING CONCEPTS Observer


There should be a person on the safety boat who watches the tow and alerts the operator if any problems develop. This person will tend the towline and transmit information to the operator, while picking up or releasing a tow.


Speed and Length of Tow


These factors will be affected by whether the boat is being towed in rough or flat open waters, a channel, or an anchorage. The towing speed should not put any boats in danger, including other boats operating nearby.


A longer towline enhances the ability of a line to absorb sudden loadings. In open waters, towing speeds may be higher with a longer tow length, but if the towed boat takes excessive water over its sides, or slams into waves, or surfs down waves dangerously, or the towline is excessively taut, these are signs of excessive speeds.


Towing at too slow a speed may cause the towed vessel to accelerate on each wave or swell, causing the line to go slack, then taut. In this case, increasing the speed may even out the strain on the towline. Typical towing speeds may be at the maximum wake-producing range of a towboat, so while operating in anchorages, no-wake zones, and close to the shore or a dock, speeds should be slowed to minimum wake speeds. Transverse waves generated behind a towboat may affect the positioning of a boat being towed, and if a towboat increases its speed these waves will move further aft and the towline may have to be adjusted to reposition the tow.


Often at higher speeds, a planing-type boat is towed near the top of the backside of the second or third wave to avoid having it surf down the face of the wave and possibly broach out of control, or ram the towboat. With heavier displacement-type boats, it may be beneficial to position the boat on the forward side of the wave to take some of the strain off the towline and towboat. If towing in a following sea, the towline should be adjusted so the boat being towed is positioned on the wave to coincide with the position of the towboat, so that each boat slows together as they climb a wave and accelerate together while coming down a wave.


Transverse waves at higher boat speed


Transverse (stern) waves at higher boat speeds will be larger and farther apart than waves at lower boat speeds.


Transverse waves at lower boat speed


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