Dealing with hydraulics for a living hoses are recommended to last a year by most hose manufacturers even though they can last for decades without any problems.
Most low pressure hydraulic systems up to 3000psi will use
single wire hose however two wire is much better even though it might seem like over kill. A good four wire hose is mostly used on high pressure hydraulic applications 5000psi. Aeroquip and Parker make flexible two wire hoses and for
marine applications I would go with
Stainless Steel fittings the hose wires are surrounded by rubber so don't worry about them. You can get covers for the hose. They help with abrasion and when a hose blows helps by keeping the
oil mess less messy. Remember once the rubber has cracked it exposes your first wire braid which will rust out quickly and if you have a
single wire hose...pop. Once the first wires go then the next rubber coating is exposed then the next wire braid and so forth.