You absolutly can but it's a really stupid idea. There are a couple of places there are major problems.
1) Stainless only retains its corrosion resistance in areas where I has access to lots of free oxygen. So any standing or stagnant water
will destroy it. Anywhere that something rests on the deck
(like under deck
hardware) becomes a major concern.
2) stainless that is submerged in salt water
has a different electric
potential than stainless in air. So the entire hull
will suffer from massive galvanic corrosion (wet vs dry) and at the boundary line you will see lots of intergranular corrosion.
Al of these things can be generally contained, but it would take a massive amount of continuing work to keep it up. It's far easier to use mild steel and paint
Titanium hulls are a completely different issue. It's an ideal material, but incredibly expensive and difficult to work in (for now). But if you don't care about cost there is a good argument to be made that it's a great option.