Fishing rod contraptions for tenders?

I was going to post this last night too but i did not want to seem so perseverent or bugg to many people at the time. I think i asked something relating to this a little while back but i wasnt sure if anyone replied. I wanted to know if the fishing rod looking things that we see on the side or on the bathing platforms of yachts used to keep tenders from coliding with the hull, are they reliable? Do they work good, what are they made from?....how big a tender can they hold?....are there any websites to the manufacturer of these devices that i can learn more about them?

Thanks everyone for your input, it really helped me to understand better. I seriously thought these things were in adequate for tenders...but now i see differently....i did not even know that they could be mounted from a dock either. For yachts though? the 'whip bases' are permanently fastened to the yacht?