Never done it but have often wondered about it off a yacht ( nothing quite like being on an 11m yacht in 15 to 20 knots wishing you were kiting!!) - seems that a bit of gear that looks like some kind of weird dildo called a Turbolauncher (Google /youtube it) could be handy to set up line properly before jumping over the side. Pumping up the kite on board in kiting wind could be problematic !!
I'm most concerned about the landing of the kite- seems that a 'self rescue' approach would be the best way of not shredding the kite in Yacht rigging etc - but either way you still need to be able to get back onboard with an inflated kite

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I assume you are looking to launch of a moored boat ? A moving boat adds another dimension!!