your code
octopus(50,100,600,100);
octopus(50,150,600,150);
octopus(50,200,600,200);
octopus(50,250,600,250);
octopus(50,300,600,300);
octopus(50,350,600,350);
octopus(50,400,600,400);
octopus(50,450,600,450);
submarine(50,400);
octopus(50,350,600,350);
octopus(50,300,600,300);
octopus(50,250,600,250);
octopus(50,200,600,200);
octopus(50,150,600,150);
octopus(50,100,600,100);
octopus(50,450,600,450);
octopus(50,450,600,450);