bowtie,
I just finished setting the posts on my dock. I went with 10 and 12 foot 4x4 treated posts. I set em 2 feet in the ground with an 80lb bag of concrete on each one. The walkway will be 5 feet wide and the posts are spaced at 6 feet. Not cheap, but less expensive than anything else I could do on my own. I think you will find that steel prices have recently gone thru the roof. I also like Bob's pvc idea, but just couldn't figure out how to make it work for my spot.
