Yes you're right. Idk how but I found Linus's forked repo first and saw on a couple websites that he did start the development for it.

A bit of history:

In fall of 2011, when a forced lull in kernel development gave him a chance to start a new project, Linux creator Linus Torvalds decided to tackle his frustration with the lack of decent divelog software on Linux.

Linus worked with a team of developers, and Subsurface is the result. It now supports Linux, Windows and MacOS and allows data import from many dive computers and several existing divelog programs. It provides a quick and easy way to see the key information provided by a modern dive computer and lets users track a wide variety of data about their dives. In fall of 2012 Dirk Hohndel took over as Subsurface maintainer.

License: GPLv2

https://subsurface-divelog.org/

https://www.deeperblue.com/scuba-meets-information-technology-with-linus-torvalds/