boat trailer question

[oteps]

My problem probably is backing the trailer in too deep along with the rollers not adjusted right. I normally winch it the last 6 or 7 feet. I would like to be able to load it myself easily. My wife wants to go fishing next year and my son will be old enough to take along. Normally I have someone pull the trailer out while I stand on the dock and try to hold the boat in the right place. One of these days I will fall in and get ran over by the trailer.
What are those guide poles made out of? The ones I have seen are pvc but they were for smaller boats. They look like they would just snap off. remember I am a new boater, I might just run into them.
Thanks for all of the comments, i would like to get this thing figured out this fall so I am ready in the spring.