if it is a production boat the flooring
is probably plywood
with a very thin laminate applied to look like laid decking.
great care is needed when sanding
so as not to go through the fake laminate.
other wise treat it as you would any paneling for varnishing ie sand and clean to remove loose varnish
and oil/contanimates,apply 3-4 coats 2 pack polyeurathane or 6coats yacht varnish, thin the first few coats.
if you can lift
and work on them in a dust free room once sanded.
if you can spray the panels
and interiour flooring there are some good laquer isocynate coatings available,that cure to give a very hard finish,though care is needed as the vapours are very dangerous.