I have a Sea Ray 2004 Sundancer...

[Bill1]

I have a Sea Ray 2004 Sundancer 260.

What is the best product for removing oxidation from the hull and restoring the original shine?

[Scott3262]

It really depends on the level of oxidation. Mine was minimal but I used a medium one step compound, then finished with a coat of wax. Both applied with a variable speed polisher.

[wrvond]

Elbow grease. 😉
Products that you can use are many and range in price from (relatively) inexpensive to the ridiculously expensive. Currently I am using Marine 31 products, but came across some really good stuff (McGuire's) at Harbor Freight that I'm going to switch over to when what I have runs out.
More important that what brand of polish you use is the process you use. I have a Porter Cable DA polisher that I use with three foam pads. I get the pads from Autogeek.
First, thoroughly wash your boat. Use Clorox spot cleaner to remove any stains while washing. Rinse well and dry. Then, using a firm foam pad (usually red) apply a deep cut polish. Marine 31 and autogeek both have good videos on how to polish. You can use a spray bottle of water to mist your working area occasionally, as long as the polish is wet, it will continue to cut. Once you are satisfied you have removed all the oxidised gelcoat, move to a medium foam pad (usually blue) and a fine cut polish. Finally, using a soft foam pad (usually white) apply a sealant/wax. Don't forget to have plenty of microfiber towels on hand. You will use several towels throughout this process. Always start with clean dry towels, and don't use a towel from the deep cut on the fine cut or the fine cut on the sealer, etc.
Plan on spending a couple days on this project.
Good luck!
BTW, my 270DA is a 1995.

[Bill1]

Thank you for the good advice