I love the Navy we do many things but the main strategic task of the navy also may incorporate nuclear deterrence by use of submarine-launched ballistic missiles and other field of work. 
I don't know much about the Navy. My best friend's husband used to serve in the Navy though.
I respect all Navy vets, The main role of the Navy is the projection of force into areas beyond a country's shores take for example, to protect sea-lanes, ferry troops, or attack other navies, ports, or shore installations.
So they spend a lot of time on the sea rather than on land?
It varies depending on what type of mission they are called out on, But most of it is on naval batleships where most troops are stationed. 
That sounds awesome! So are you in the Navy too?
I was in the Navy years ago, most of the navy I know of is force or fleet of waterborne military vessels such as the battleships I mentioned and its associated naval aviation, both sea-based and land-based.