No perspective correction used - in this case I was able to ensure that the verticals didn't converge by merely using the bubble levels on my tripod. It helps that the ramp out to the float made it possible to set up at near half-height of the pilings.
The dock is at an end of what used to be one of two main channels of the Fraser River, but is now just a fairly long arm of the river that no longer connects to the other main channel at that end. It does raise and lower with ocean tides, but not nearly as much as the pilings would indicate.
The main use of the dock is as a launching place for multi-person rowing skulls. A number of competitive rowers use this waterway as a practice facility. I've wondered if the high pilings are there because the bottom is soft, and because it may be necessary to "adjust" their height over time.
And yes, I'm new to this mat cutting business, so my corners are inconsistent at present - I'm learning as I go though, so hopefully anyone else getting matted prints from me in the future will see little or no overcut.