Water Waves in the Wake of a Boat As a boy I noticed that the waves from the wake of my model boat would fan out. If I looked at the end furthest from the boat the front had turned so that it was almost running in the same direction as my boat. 

The wave also appeared to bend in doing this in exactly the opposite way that I'd expect; waves from a stone thrown in a pond are circular so I'd expect waves from a boat would bend 'backwards' rather than bending to almost run parallel with the boat. I've found a video on You Tube that shows this rather well, if briefly:- https://www.youtube.com/watch?v=PP35lbrx0JQ The example starts at 2'55". I've search the internet in vain for an explanation. I think it may be an illusion because the distance between crests increases with time. Can someone explain this to me please? Also, are the wave crests accelerating? And if so what's causing it? Thanks ever so much if you can.  
 A: First up thanks to all who took an interest especially @irishphysics who stuck with the question for some time.
It turns out that the phenomena was analysed and solved by Lord Kelvin and is known as the Kelvin wave pattern. The pattern itself is the result of a spreading pressure wave which manifests itself as the curved diverging wave crests (the ones I described as bending in my original question) and a set of transverse waves that sort of follow along with (and behind) the boat. 
The full (mathematical) explanation is here: (https://www.math.ubc.ca/~cass/courses/m309-01a/carmen/Mainpage.htm).
The final (modelled) wave pattern from the above link looks like this:

which for me is pretty close to my experience.
For those who suggested the depth of water had something to do with it: you were partly right in that the precise angle of the waves from the bow depends on the depth of water rather than on the speed of the boat.
There's also a good explanation of the physics here:-
(http://www.prirodopolis.hr/daily_phy/pdf/speed.pdf) 
A: From this link below " Refraction is the bending of waves because of varying water depths underneath. The part of a wave in shallow water moves slower than the part of a wave in deeper water. So when the depth under a wave crest varies along the crest, the wave bends.               
See "http://www.coastal.udel.edu/ngs/waves.html
So my guess is its due either  to variations in water depth or else it's an optical illusion. If you can check it easily, I would bring a measuring rod, and do measurements all around the area below where the wave bends.
Conservation of energy is paramount here (as you know), so no matter what we think we see, if you hold your boat at constant velocity, in reality, that wake is going to dissipate sideways only, never backways toward the boat, over time.  So unless there is another force present to give the wave more "kick",   the bending must be an optical illusion, no matter how many observers agree that they saw it.
So what possible forces could push the wake back towards the boat?  Normally it would spread out wider and wider as the boat moves further away, but to change direction back towards the boat needs a force and unless the change in depth  idea is true, see the link above, there is no other force to cause this reversal in direction. If the depth of the lake is constant, that it adds support to the illusion idea.
I have no experience of water wakes, (other being a passenger on ferries and rowboats) but it does seem to me that water waves, like mirages and rainbows, are a much likely cause of optical illusions that anything static,  merely because there are just many more variables involved.  
So to sum up, unless you can test the depth to ensure it's constant, and make sure that no other forces, such as a wind blowing towards the boat, are involved, I would make put my money on the illusion explanation.
