submerge: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/submerge - from package: subcommander

You may install the required package with command apt-get install {package}

Error in other languages:
submerge: bevel nie gevind nie
submerge: comandă negăsită
submerge: comando não encontrado
submerge: commande introuvable
submerge: command not found
submerge: käsku ei ole
submerge: không tìm thấy lệnh
submerge: komanda nerasta
submerge: Kommando nicht gefunden.
submerge: kommandot finns inte
submerge: komut yok
submerge: nie znaleziono polecenia
submerge: níor aimsíodh an t-ordú
submerge: no se encontró la orden
submerge: no s'ha trobat l'ordre
submerge: opdracht niet gevonden
submerge: parancs nem található
submerge: perintah tidak ditemukan
submerge: príkaz nenájdený
submerge: příkaz nenalezen
submerge: команда не найдена
submerge: командата не е открита
submerge: 命令找不到
submerge: コマンドが見つかりません