With a black felt-tip marker, make 1cm. markings on the straws. Each centimeter represents one mile of ocean depth. Do this on the graph paper on the shoe box lid as well as on the second sheet of graph paper on which the student will record their soundings. Exchange shoe boxes with another team. Using the graduated straw as a plumb line, measure the depth of each hole in the shoe box lid.
Students start at the far left and top and work their way across the graph paper.
One person makes the sounding and reads off the depth of each hole, while another records it on graph paper. Record the depth of each hole on the graph paper. When students have completed taking all the soundings, have them draw lines to connect all similar depths. Then have the students use different color markers for each depth. Ask them to name the ocean features they have mapped, such as hills, valleys, plains, etc.