Manipulating a boat wake...

[Brandon]

A few years ago I was perusing the "Big Issue" that surfer put out...somewhere inside I recall an image where Tom Morey (something of an explorer in the world of hydrodynamics) had affixed a wing of sorts to a track that was immersed in a long water tank. He then used a ford truck to motivate the wing through the water thereby creating a wave of sorts with actual forward trajectory. I have often envisioned something like this to enhance the 'breaking' shape of a wake as produced by a boat that is produced for 'wake-surfing'. I realize the nature of this discussion may be seen as too 'low brow' for some of the forum attendees but I would imagine that those particularly interested in wave dynamics would be able to offer some well informed opinions on the matter. If I come across a picture I will post it for reference, so far I have come up empty handed in my search.

[jehardiman]

A wave is nothing more than the physical manifestation of a pressure distrubance in a fluid at the boundary between two fluids of different densities(air/water or water/water). And there are many ways to make them.

The important thing to remember is that the amount of energy required to make a wave is proportional to its celerity (speed of advance; which is a function of period and water depth) AND the height squared. As a boat makes a wave by moving through the water at the speed of the wave, there is a very steep energy price to pay for making a taller as opposed to longer (i.e. faster wave). I.e. to make a 15 knot wave 1 foot high in 100 feet deep water requires 1025 ft-lbs of energy per foot of wave frontage which means that ~95 hp are required. To make a 20 knt 1 foot wave requires ~227 hp. To make a 2 foot 15knt wave requires ~381 hp.