yup but at $4 a tube, its cheaper to do epoxy or rubberized paint. And 100% silicone you have a window to work with before it starts to chunk up when you spread it. And if you wait that long you pretty much compromised your water tight seal.
I was building a 90 gallon tile tank and I used if I remember 5-6 tubes of caulk just to seal the window and the grout lines. So $25 just for sealing things up from the plywood. I think if you were to seal a 55gallon plywood it would cost $100 in silicone itself.