This is an age-old question that is full of half-truths so in this article we are going to go over the facts about aluminum hulls vs. fiberglass.
Let’s begin by addressing the weight issue. Aluminum hulls are typically twenty percent lighter than fiberglass and that also converts into savings on fuel costs and that also means better performance. One of the myths is that a heavier hull will ride softer but that is not true. It depends on the angle of attack of the bow and how it splits the waves. Just look at a Coast Guard patrol boat and they are all metal and yet they have a very soft ride compared to most composite boats. This again comes from a sharp bows dead rise splitting the waves and the weight really does not have much of an influence. The bow works just like a knife! If it is sharp it will split just about anything but if it is dull good luck on splitting a stick of cold butter!
Another common myth about aluminum hulls is they are square and not attractive. Again this can easily be disproven by looking at all the mega yachts that have beautiful lines and are mostly constructed of metal. The shape is determined by the designer and the skill of the crafts people who build the boat. Another example is just look at most cars and they are made from metal and are very stylish. A boat is only as attractive as the designer plans it to be. One of the reasons aluminum boats are square is many are built by welders who do not have a design background.
If you have heard aluminum is maintenance free then that is also false. Actually fiberglass is easier to maintain then metals metal boats. There is an issue called galvinetic corrosion that occurs with metals that is caused when two dissimilar metals come into contact with each other. In aluminum boats this typically occurs when stainless steel hardware is used and what happens is these two metals have a different electrical charge that literally makes them act as a battery and that causes the metals to decay. Most boat owners are familiar with this concept from the sacrificial diode mounted on the motor that decays over time.
Aluminum is superior in terms of the paint chipping from activities like beaching and hitting unforeseen objects. Fiberglass has something called a gel coat that makes it shine but it is also very delicate and can chip without much effort. On the upside for composites they can easily be repaired and buffed out to shine again.
In the end either type of boat is a good choice but if you plan to beat up the boat and get rough with it a metal boat may be a better choice.