This is luizribeiro's collection of Debian packages, mostly for Raspberry Pi OS.
First download and trust luizribeiro's GPG key:
curl -sL gpg.l9o.dev | sudo apt-key add -
Then add the apt
repository to your system:
echo "deb https://ppa.l9o.dev/raspbian ./" | sudo tee /etc/apt/sources.list.d/l9o.list
sudo apt update
Once that is done, you should be able to install packages from this repo, such as mariner:
sudo apt install mariner3d