your code
diver(500,100,450);
submarine(100,500);
urchin(500,50);
urchin(550,50);
urchin(550,100);
urchin(450,50);
urchin(450,100);
urchin(550,150);
urchin(550,200);
urchin(550,250);
urchin(550,300);
urchin(550,400);
urchin(550,350);
urchin(550,450);
urchin(550,500);
urchin(500,500);
urchin(450,500);
oxygen(500,450,300);
urchin(450,450);
urchin(450,400);
urchin(450,350);
urchin(450,150);
urchin(450,200);
star(500,400);
oxygen(500,150,400);
urchin(450,300);
urchin(400,300);
urchin(400,200);
octopus(350,100,350,350);
urchin(400,350);
urchin(400,400);
urchin(350,400);
urchin(300,400);
urchin(300,350);
urchin(300,300);
urchin(300,200);
urchin(300,150);
urchin(300,100);
urchin(350,100);
urchin(400,100);
urchin(400,150);
urchin(250,200);
oxygen(200,100,400);
star(200,120);
urchin(250,300);
urchin(250,150);
urchin(250,100);
urchin(250,50);
urchin(200,50);
urchin(150,50);
star(350,250,"red");
urchin(250,350);
urchin(250,400);
urchin(200,400);
urchin(150,100);
urchin(150,150);
urchin(150,200);
urchin(100,200);
urchin(150,400);
urchin(150,350);
oxygen(200,350,400);
star(200,340,"red");
urchin(150,300);
urchin(50,200);
oxygen(350,150,1000);
urchin(50,250);
urchin(50,300);
urchin(50,350);
star(100,300,"pink");
star(100,350,"purple");
urchin(50,400);