A successful answer to the question you ask will be the driving force to kick the activity of kiteboarding into the stratosphere... that is ... The ability to safely launch a kite from any body of water, anywhere there is wind!
Many have tried ...many have failed...
Here is a copy of one of my posts from the following thread: viewtopic.php?f=1&t=2347385&start=10&st=0&sk=t&sd=a&hilit=self+launch
A lot has been posted in the past of this forum concerning the question you posed:
If you take the time to read and follow through all the inclosed links, you will have been exposed to essentially all the ideas that have been presented in the last 5 years concerning this topicâ€¦soooooâ€¦.set aside about 3 hours, grab a six-pack, lock yourself in your study, and have at it!
â€œYou may find some of the information in this thread useful in setting up a system to launch in your situation. The seaweed may be the biggest problem. Setting up a little anchored floating platform like Wetstuff describes could work in your situation, to allow you to launch off your 5th line. You could consider making a Line Tender out of PVC, as described in the post. This would work better in your situation than a Turbo-style-launcher, for unwinding the kite-lines while walking the kite from the platform back toward shore, in order to properly position the kite.
Here is another launch technique you may want to consider. I developed this method and the necessary â€œbelayâ€ tool in order to launch from some very difficult places in the Gorge. It worked fine, but demanded some hours of practice, and of course the time and effort to construct the final version of the â€œToolâ€. I call the technique the â€œDriftfly launchâ€, because the kite drifts a little bit and then flys up. The flying up is necessary to shake off the seaweed. A normal drift launch in a bed of seaweed is risky.
I presented a description of various versions of the â€œtoolâ€ in the following thread, the version I presently use is shown on page 2:
If you get really desperate, then, just before you resort to buying a â€œlaunch boatâ€, you might want to consider the possibility of constructing and using the â€œPipe launcherâ€ as presented in this thread. This is about as unconventional as you can get: