On a 48, it has to be cut in half. Just finishing up the removal and replacement of both tanks on a 1986, 48 super sport.
The port tank is fabbed and installed as one tank. The starboard tank is two tanks with added volume to match the original tank. I have photos for reference if you need them. The issue on the starboard side is the main elect panel and cabinet. It was far easier and less expensive to split the tanks.
Here are a couple of over view photos, the entire floor and sub structure has been removed to facilitate the tank removal and installation.
Basically it was cut into quarters, with the top removed the interior was cleaned to minimize a mess when the lower portion was cut in half. As you can see the new tanks were sized so they could be installed and placed after they were fabricated.
Generally on Oceans (as they're saddle tanks under the engine room vents) when one tank fails, the other is only a year behind it. Change them both at the same time.
Do you have the specs for the two tanks on the starboard side? I need to replace the tank on my 48 ocean as well. Thanks