In constructing and using any of these self launching devices..."The devil is in the details"...and the details are not always apparent at first. When I considered the problems inherent in a launching device with an exposed line, my imagination ran wild with images of (1) accidentally tripping of the device by the kiter or an outside force. I have had a big dog swim through and tangle all of my five lines on different parts of his collar and legs. The kite came very close to a uncontrolled hot launch. Other kiters also come in to land their kites at the most inconvenient times, not to mention motor boaters.
I, therefore, rejected any form of unshielded and unprotected release cord. I first pictured a device that was entirely buried in the ground...a long pipe with two upright stand pipes with the release pull mechanism at one end at a marker buoy, and the kite temporarily secured at the other end. There were problems with this design, and I rejected it.
One of the "devils" to be dealt with in the exposed rope release design will be the fact that risk will always exist of the rope (if it is a sinking rope)snagging on not just one rock, but on many rocks on the bottom. If the type of rope is a floating rope, it will tend to lace and braid itself into the 4 kite lines, on the surface. This is the reason I placed the slotted line guide floats along the Pipe. Nontentioned floating lines do not behave well and have a propensity to tangle, and the more lines involved, create more possibilities of combinations of loops and braids.
Another "devil" will be that of the rope being jiggled by the waves and forming a loop which will snag on the ring at the pump leash, or will drag some of the kite lines through the ring, hobbling the launch, part way through the launch, while the kite catches a gust and prematurely works its way to the edge of window, into a premature launch.
Any aspect of the design which neglects such factors as the examples above, will result in the necessity for some fast and clever on the part of the kiter, as things go from bad to worse. Every possible thing has to have a high degree of control.
I could go on and on, but I fight the urge to do so.
Up to this point you have rejected the idea of putting a 5th line on your bow kite, as I did. Adding a 5th line, however, in order to allow a less complex self-launch procedure was the compromise I eventually opted for.
This thread is not about 5 lines, but 4 lines.
I neglected to finish the description of the pipe launcher, but still plan on describing the procedure, the kiter must follow to use the device. I was interrupted in my presentation, by involvement in a bunch of other threads on this and other kite forums, but plan on continuing with a couple more posts in a few days or so.