We launch from sea in Denmark, east of Bornholm in the Baltic Sea. We like the idea of launching (and landing) on water. If we are able to control this environment we are basically able to launch our rockets from anywhere in the world to any height.
The basic problem that keeps most amateur rocketry projects from reaching high altitude is that of a suitable launch site. Northern Europe is very densely populated, and there are no areas like the Black Rock Desert. Even if we did have deserts here, the regulatory regime of private, amateur spaceflight is Terra Incognito to authorities.
However it has been discovered that outside the national territorial waters - typically 12 nautical miles off the coast - things gets a lot simpler from a legal perspective. In the practical world the open sea also offers a lot of interesting features to us.
Few landmasses on the planet is as empty as the open sea - and as easy to monitor. This makes the whole issue of range safety relatively simple compared to the conditions on land. Most space ports are found on a coastline for the same reason. Finally - operating out of Copenhagen, Denmark - the logistic challenge of launching rockets from Sahara or some place in the Artic is much larger than sailing a couple of hundred nautical miles out to sea.
As a result, in 2009, we decided to commit Copenhagen Suborbitals to sea launch.
Last year they ran into some problems when they called the danish navy and asked 'is it ok with you guys if we tow our 115000 horsepower rocket through danish territorial waters using the largest homebuilt submarine ever built?'
unsurprisingly, the initial answer was that it was not ok. They got it solved though.
There seems to have been some negotiation this year also, due to a conflict with a NATO training exercise. In the end they ended up getting permission for a five-day window, according to this Danish article (Google Translate link): http://translate.google.com/translate?js=n&prev=_t&h...
