I replaced the batteries on my 2004 Grady White 228 Seafarer back in the late fall/early winter of 2023. I called up my local Grady White dealership and they recommended that I just buy new batteries of the same size, style and so forth that I currently had. My boat had/has two starting/cranking Group 24 batteries, of which I replaced those with the exact same thing, two Interstate brand Group 24M-XHD batteries. This will be the start of the third season with them, and besides a loose connection at the battery terminal when I initially installed them, no issues so far, knock on wood. If you don't know off the top of your head, I'd double check to see what size and style of batteries are currently on your boat. Then replace those with new ones of the same size and style. I'm sure that there will be several along here shortly with battery brand recommendations and so forth, of which I've had good luck with Interstate, and they do sell some of them at Costco or your other local big box stores/warehouses. Some will likely recommend the AGM batteries, though when I talked to my local GW dealership on the phone about replacing the batteries, I asked about the AGM's and the tech didn't recommend them. He mentioned they were about twice as expensive as the regular wet cell batteries and didn't seem to last all that much longer to justify the additional costs. Good luck!