I have a ton of pipes on my boat, with central hydronic heating plumbed to five or six fan coils on top of hot and cold water supply.
It was all done originally in a UK system similar to pex called Speedfit. It was beautifully done by the yard and functions perfectly after 12 years of use, BUT -- I also had to change a calorifier
this year, so had to do a lot of attaching, detaching, attaching pipes and some replumbing to accomodate the different configuration of the new calorifier
The Speedfit system is not perfect -- the fittings are theoretically not reusable and can be tricky to screw back on. It is not reasonable to not reuse them because they are not cheap
at all. My second complaint is that there are several competing systems like this in the UK, and they are all subtly but definitely incompatible. So it can be a lot of hassle.
I now carry about 6 meters of the pipe plus a large collection of the fittings on board, in case I ever have another situation like I did with my calorifier last spring, which is a real octopus of pipe fittings with two different coils (from central heat plus from engine), water in, water out, pressure release, etc. I got a lot of experience with the Speedfit system!