Upload this ZIP to /var/www/app.yachtmemory.net and run:

cd /var/www/app.yachtmemory.net
unzip YachtMemory_2C2b4_install.zip
chmod +x YachtMemory_2C2b4_install/install.sh
./YachtMemory_2C2b4_install/install.sh

The installer backs up replaced files, installs and syntax-checks them, then
moves all ZIP files from the application root and the extracted installer into
archive/install-packages/<timestamp>_YachtMemory_2C2b4_install/.
It performs no YachtMemory database writes.