|Seaway for sea transport related features like ports|
|Status:||Draft (under way)|
|Tagging:||seaway=cargo_port, cruise_port, ferry_port, fishing_port|
|Definition:||a key for features related to the navigation at sea|
This is a proposal to introduce a new key with a sea transport related scope. This can currently be seen as kind of brainstorming (feel free to add your own ideas, also on the discussion page), although you are invited to already use these tags if you find them helpful.
Currently there is an appearent lack of tagging structure in this field. Features can be found in keys like Template:Seamark or implicitly by looking at landuse (industrial=*, a landuse subtag), but with few structure and some gaps in the scheme we currently miss a lot of interesting information and details about the infrastructure for navigating the seas (e.g. compare global tag usage numbers of airports to those of seaports).
This could have also been something in an established key like man_made=* or amenity=*, but if you look at the whole OSM tagging scheme, you can see that all similar (transportation infrastructure related) features have their own key: highway=*, railway=*, aeroway=*, aerialway=*, waterway=* and it seems logical to introduce the missing link for sea based transport.
Use the key seaway=* with one of these values cargo_port, cruise_port, ferry_port, fishing_port (see below for more information) and add other relevant tags like:
Add subkeys according to the kind of facility you are dealing with (see below).
Add properties to describe the cargo handling capabilities:
|cargo:container=yes/no||port can handle standard cargo containers|
|cargo:bulk=yes/no||port is able to handle bulk cargo, i.e. stuff that isn't packaged, typically granular)|
|cargo:liquids=yes/no||port for the handling of liquid cargo|
|cargo:gas=yes/no||port for the handling of gaseous cargo|
|cargo:break_bulk=yes/no||port is handling break bulk cargo, stuff that has to be handled individually, e.g. cars, bags, boxes, barrels, crates, drums|
|cargo:heavy-lift=yes/no||port can handle heavy-lift cargo, e.g. plant components|
|seaway=ferry_port||for ferry ports and ferry terminals.|
|seaway=cruise_port||for cruise ports and terminals.|
- ferry_port=yes/stop/terminal (in case of the port being both, an intermediate stop and a terminal, use terminal and add the details in the ferry route relations)
- cruise_port=yes/home_port/terminal/port_of_call home_port for the home port of a cruise route, terminal for a route endpoint (not being a home port) and port_of_call for a port that is "in the middle" of a cruise route. Use home_port in all combined cases where it is also a home port, and similarly terminal if it is not a home port but a terminal.
terminal, home_port, stop, port_of_call could also be roles in the routes, if they are mapped. For combined ports use the most important function for the main tag (seaway=*_port) and add the subkeys for further detail.
|seaway=fishing_port||for a fishing port by the sea.|
Use inland_port=yes/no together with a seaway=* port type (see above) for inland port facilities that handle ocean-going vessels.
Use waterway=port for inland ports like river ports and ports at lakes for river traffic, such as barges and other shallow-draft vessels
On the tagging ML: 
Please comment on the discussion page.