Doesn’t seem that onerous. That’s 40£ of wood plank, 4 bags of cement, and some steel bands you can find at nearly any metalworks shop. I think the bigger worry is a corps that isn’t properly weighed down can turn into a very expensive police investigation. They won’t know if it’s a sea burial, drowning, or a crime.
It's not the financial load, it's the environmental / CO2 load that takes an exit with negligible impact and gives it significant impact. Ignoring any boat mileage of course, the wood may be sustainable and low impact, but neither steel or cement are when used as single use packaging. :)
Relocating a few bits of sandstone in a canvas bag is trivial by comparison. Just as well sea burials have become pretty rare these days.
Profligate is profligate regardless of whataboutism. Every activity should make effort to be sustainable, and must convert to being zero carbon if the climate crisis is to be averted. That includes burials.
Besides someone may be considering burial after they've already changed lifestyle as far as possible.
