Nowadays, people use this for any situation, not just on a boat. Hands means any nearby people or workers and deck means the location of the speaker or event.
This expression has a naval origin. Hands is another word for sailors and deck is a part of the boat. In a storm or other emergency situations, the captain might yell "all hands on deck." This is a command for all the sailors to come to the deck of the boat to help navigate the emergency.
I truly believe at this time God is saying “All Hands on Deck”. God is summoning us all to duty. God is reminding us that we need to desire souls brought into God’s Kingdom. Jesus is coming back for a church that has made itself ready. Jesus’ call to evangelism must stir us deeply in our hearts. There is a battle raging all around us. God is seeking those who would become his children and the enemy is blinding the eyes of the unbelievers (2 Cor 4:4 - The god of this age has blinded the minds of unbelievers, so that they cannot see the light of the gospel of the glory of Christ, who is the image of God). We are in a battle to see the Light of Christ manifested in new converts for the Glory of Christ. The enemy seeks to blind our eyes through idols – anything that replaces God, takes His place, through various forms of entertainment, addictions, materialism and even religion.
I believe God is saying to us “its time to get back in the battle, “All Hands on Deck”… There is something eternally profound about our relationship with God; He saves, He forgives, He makes people brand new - transforms and sanctifies, He heals, He directs. God is committed to fully saving His children for His Glory. The ministry of evangelism is something we all have to engage in, it is a group effort.
Now! Let's put “All Hands on Deck” - let’s be committed to the plans and purposes of God. You needed as the time for this world is winding up.