I looked at blitzortung.org once because I was interested in detecting lighting while being on a boat. Especially to know the distance (the direction can be seen).
But a device can only measure the moment of discharge. Only in combination with other devices a position of the lightning can be established.
Maybe somebody wants to have a go at this. Because there are a lot of very expensive boats out there. Especially the ones with carbon masts...
The data is small enough you could receive the stream over Inmarsat or Iridium. And before you rebutt cost, I know exactly how much those carbon mast boats cost.
The other devices (preferably more then one) should be on other boats to be effective out on the oceans. So there is bit of a chicken en egg problem: not very useful if you are the only user.
It would be a project to discuss with a big freight company. One that has already many boats out there anyway. Maybe to get it started and financed.
Never knew of XM weather. But the reception is only in US & Canada so I guess only interesting for coastal areas ? Nevertheless, I wonder where they get their lightning data. Which is US-only according to the website.
If you click the "Stations: off" button it shows participating stations. Stations that measured the lightning strike are indicated in purple for a short moment.
'Lightning data by Blitzortung.org and contributors • Blitzortung.org is a free community project'
The data is collected by volunteers who have a certain device at home which is connected to the internet. Its doing this for several years now I think.
http://www.diaart.org/sites/main/lightningfield
https://en.wikipedia.org/wiki/The_Lightning_Field