Its a long way to go before we start seeing the interest in developers making addon's for ship simulator, firstly a lot more code needs to be published, so that addon developers can make their own playable maps, be able to change the water textures or add better crash dynamics for example.
Secondly most Flight Simulator addon's cost roughly £19-£30, while Ship Simulators 2008's addons are only £4, this is because the level of detail is accurate, with real insturments being simulated and real dynamics being used to simulate its real life counter-part, as most flight simulator addon developer's want to make a profit from their work. And when they have a choice of making something their use to (another flight sim plane or airport) than going into the new making a ship which will be half the price if they had of launched a flight sim plane instead, they are going to stick with something they are comfortable with.
I see the way forward in terms of player/addon development is for VSTEP to launch its own, "Ship Editor" much like it's Mission Editor, where the player/user can create his own ship using a simple/basic user interface. A bit like what X-Plane does.
But to be honest, VSTEP have already included a wide range of playable ships ranging from tankers to cruise ships. So I think most people are happy with what they already have.
I hope this explains in my opinion why I think Ship Simulator is lacking in addon development.
Oasis