It might be possible depending on the type of boating and fuels used on the boat. SmartThings needs stable Internet connectivity, this is something generally not associated with boats. If you have an always on hotspot from your cell service that might work, assuming your boat is always in cell phone range. Typically smart phones with hotspots are not good as they time out their internet connectivity after so many minutes and the hub is guaranteed to be used in that window. The hub itself isn't marine grade so it would definitely need to be kept out of any damp or hazardous areas. And the hub comes with a 120 Volt adapter, which itself may be an issue if your boat is mainly 12 volt.
The other question is what are you trying to get this to do? If you want it to remotely turn things on and off the target device would generally have to be 120 volts. I'm not aware of any zigbee or zwave relays that function as a 12 volt relay for a 12 volt switched connection. And of course, that relay would have to be up to marine standards because relays tend to spark when they switch off, which isn't a good thing if your boat is gasoline powered or has propane appliances.
If you are looking for this to have a bunch of water sensors so that you would get an alert if your boat leaks, or starts to sink, I would recommend adding water sensors that work on battery backup, on power and have an audible alarm. The audible alarm alerts others around your boat even when Internet connectivity is down. Aeotec makes a Z wave water sensor compatible with the hub that is USB with a battery backup, and an audible alarm when it detects water.
Good luck.