Waterproof a scale boat

[Jostro65]

Hi all, this particularly relates to an Italeri 1/35 Elco I'm converting to R/C, which I haven't did before.
Although the kit has a removable deck as 1 complete piece, I would preferably have only the centre section of superstructure removable for quick access, possibly removing the fixing tabs and just secured with magnets. My main issue is how to waterproof that section as it's an irregular shape.
I've seen loads of build blogs for this exact model but none I've found give real clear pictures or descriptions of this process.
Simply saying 'instal a waterproof rim around the hole' is common but I don't really get that due to the aforementioned shape. I'm quite a visual person so pictures do say a thousand words where I'm concerned!
Any help on this would be greatly appreciated as I've stopped the build just now for fear of making a bad call.
Thanks all

[Pitar]

A few tips from my experience:

• Epoxy resin works well but make sure to mix it thoroughly and apply multiple thin coats for best results.
• Pay extra attention to seams and joints—seal them carefully before coating.
• Always test your model in water after waterproofing to catch any leaks early.
• Remember, epoxy adds weight, so keep layers thin to avoid losing detail or affecting performance.
• Work in a well-ventilated area and use protective gear when handling resins or sealants.

Thanks for sharing this—looking forward to trying it out!