Is there any way to jump across the cubes in the water?

Once you get past the first tunnel, you should notice some big cubes in the
water immediately in front of you.

Just drop onto the first cube.

NOTE: You may have some depth perception problems when navigating the cubes. 
Sometimes it looks like a cube is right next to you, when there is actually a
gap between the two cubes.  If you don't jump, you may fall victim to an
untimely drowning, so be careful and save often!

You can climb or drop onto some of the cubes, but you need something else to
transport you across the lake.

Do you have any unknown objects that may help?