Do a search, this has been discussed before.

Couple tips:

It's easier to replace the wood than to remove all the old carpet and staples.
Use indoor/outdoor carpet adhesive (Lowes/HomeDepot) on the face of the 2x6 boards and on the wood surfaces that face the boat; just to keep the carpet from bunching and tearing. Not so much to soak the carpet, just enough to hold it steady.

I don't care for the electric staple guns. They don't have enough power to shoot the large staples all the way into the wood. I had to go back and tap them all down with a hammer.

I recommend using a Hammer Tacker like this one:
[ATTACH=CONFIG]521633[/ATTACH]
You will get to a point where you can swing the Hammer Tacker at the wood at a 45 degree angle to the edge of the wood, and the swing will pull the carpet taught as the staple holds it there. It works MUCH better than the electric gun.

If you have so thick of carpet at the edges when you wrap over a couple layers, put a couple of 1" long #4 or #6 SS screws though the layers to fasten them down. Obviously, don't do this anywhere near where the boat touches.

I've used boat stainless & Monel staples before with fine results.

I need purple carpet! The only place I can find it is http://www.marinecarpeting.com/ If i remember correctly (boat is in storage) i need two ten foot pieces and two sixteen foot pieces. Plus the sides along the wheel wells. So I figure I need a 6x20 piece. Thats $175!

HD has a black cut pile that could be a good substitute for purple.

My trailer is purple. I don't know if my OCD could take the stress!

I had purchased this carpet as well. I liked the idea of a little thicker carpet. Sparta Carpet is the Ebay seller. I purchased 68ft for $100 shipped to my house. I bought 2 new 2x6x16' bunks and used the current 4x8x12' bunks as no one local had them in stock. They were in great shape and the old carpet came off without a problem.

I agree with Sydwayz about the stapler. The electric staplers just don't have the power to drive the staples in all the way by itself. I prefer the hammer stapler as well.

Thanks everyone!!!!