Service register is the part of The Maritime Cloud where we register the STM services.
Here you can find information about how to register a service. https://management.maritimecloud.net/#/pages/sr/howto
You can find all services that are available in STM under Service Instance Description
Swagger API for Service Registry can be found at https://sr.maritimecloud.net/v2/api-docs
Further textual description can be found at http://maritimecloud.net/ and http://developers.maritimecloud.net/