I have the same boat and the previous owner did this with Marine Cooler Mounting brackets. The cooler was mounted pretty much right in front of the splashwell, center. I took it out, but it was nothing fancy...the hardware was probably just #8 SS screws, maybe 1"L at the most. At that location, no concerns about hitting any hoses, etc....just drilled into the deck core. defintely put some silicone around the screws though before screwing