Seeing as the brand new James Webb Space Telescope's main mirror was recently hit by a micrometeroid, I figured that now would be a good time to ask about spaceship hull protection. When we think "spaceship" we probably imagine a large hunky piece of metal floating through the vacuum of space. Space which is filled with particles moving at high relativistic speeds. No wonder they are hunky! Since a pebble could cause lots of damage the craft would need to be well protected and every subsequent collision would give more things to repair... SO! Why not use an outer-coating of ice?
In story, I've already established that the spacecraft needs water in order to function. The engineers logic for that was "where there is water, there is life". So the ship (which is piloted by an A.I.) actively seeks out water during it's exploration of the universe. It harvests water for propellant from comets, meteors and other sources to keep it going. Hydrogen can be extracted from water for energy storage, to feed the fusion reactor and for cooling systems. So forming an outer-coating of ice would be like having a large "battery" of sorts, instead of just deadweight.
This armour of ice would give the ship the appearance of a comet or meteor, unintentional camouflage but a welcome feature. I guess if you feed on meteors the meteors eventually fight back. Heheh! Anyway... the REAL selling point of the coating of ice is that it does not need to be repaired, unlike the actual ship which is made of uncommon materials. Water is fairly common, can be melted and frozen again and can be added or removed from the hull if need be. Safe and customizable!
Oh, and if you're asking about how the ship steers with all that ice on top of it, the answer is simple: it makes holes. Drilling, microwaving, lasers... there are many options.
So the question stands: how much safer would it be?