The speed whingers
THE speed whingers have featured often in narrowboatworld but when even the gentle John Dodwell is drawn to comment on the ignorant—and commonly rude—speed obsessives (Not-sailing-off-into-the-sunset) it is obviously time that these sad people were better educated on the subject, writes David Lyneham-Brown.
Moored boats are not disturbed by speed alone but by the wash generated. Speed, hull design, water depth and channel width are the main issues that contribute to wash and the potential disturbance of moored boats.
Wash generation
John talks about his boat as having a rounded hull and in practice the design of both the bow and the stern below the waterline are key contributors to wash generation. When I designed my boat the choice of a rounded bow to reduce the push wash was paired with a long stern swim. The 14 feet swim not only improves prop efficiency and boat manoeuvrability but also very significantly reduces stern turbulence when cruising.
Water displacement by the bow goes outwards from the bow and also downwards. In shallow water that downward displacement can bounce back and add to the outwards surface wash, a factor that the boater will observe and account for when monitoring the impact of their progress.
Less distance to diminish
Where the channel is narrow the distance between moored vessels and the passing boat will be limited and the wash has less distance over which to diminish. Where the waterway is wider, especially where the passing boat is on the offside, and with consideration of the impact of wash on the nearside bank, speed can be considerably higher than tick-over with no wash impact on moored craft.
The amateur moorers contribute to their own discomfort. A fellow boater out of Reedley Marina recounts the story of the abusive, gesticulating boat owner who was moored up with just his centre rope .... pardon?—neither safe nor sensible. Another moaned every time his metal mooring hooks rattled on the Armco piling, yet close inspection revealed that instead of roping up two in or two out he had, by no more than a foot, one in and one out. Where do these people get their mooring skills from?
Situations
So there are numerous situations in which
· a well designed boat (front and rear swims)
· on a waterway that is sufficiently dredged
· and in a channel wide enough (and sightlines sufficiently open) to move past at a reasonable distance a narrowboat can pass moored craft at 3 to 4 mph. And I will continue to do so.
A good boater (and there are many around) monitors wash continually when on the move and makes speed adjustments as the circumstances merit. When the whingers sound off just shout "where's the wash?" and carry on.
To mis-quote Bill Clinton—it's the wash, stupid!