Fibreglass, Aluminium or Plastic Boat?

Without doubt, the most argued topic in boats is the Aluminium vs. Fibreglass vs. Plastic debate. It’s much like politics. A murky world of claims and counter claims, a world where some punters follow one party, others don’t, some listen to the opinions of friends, some are blind to the facts before them, some won’t go about finding out facts themselves and some have unshakeable perceptions which cloud their judgment on which one is best, if any at all? Luckily for you, I won’t be going into politics, but want to give you some opinions on boat construction, how strong they are how material affects performance and depending on your use, some ideas on why some materials will be better suited than others.

It was much simpler in the beginning. There was a time when only one material was available, wood. Most boats were built of timber as it was readily available, could be milled into various and sometimes intricate shapes and were fairly easy to process with the tools of the day. Boat building was a fine art practiced by a few who spent many years honing their skills up and down the coast at early shipyards. They used simple tools but all had a great eye for detail and the angles required to make a hull work. Wood does have the propensity to rot but it was tough and sturdy and if looked after properly would last for years.

Fast forward to today and you have more options with boats made of fancy new materials all of which are designed on a computer program. Angles are tweaked for optimum performance, decklines lowered or lifted, windscreens moved forward or back all before any tools are used in anger. You need a skilled designer, CAD operator and then finally builder to end up with a quality finished product but modern technologies mean less guesswork and computers have resulted in ride angles and hull designs that are far more precise than was ever possible before.

Most boats are now built from one of three main materials. Fibreglass, Aluminium or Moulded Plastic. It is true that certain construction methods employ hybrid technologies such as sandwich technology and vacuum bagging but for the purposes of comparison we will consider these three as the main construction types. Each has its own plusses and negatives and let me be the first to tell you that no single construction method is perfect for all uses or environments. As with most boats, selecting a construction material is more a process of compromise than outright suitability.

Compromise is an essential tool when selecting a boat. There are many things you may like to do in a boat and boats are designed to be great at many tasks, and rarely designed entirely around one perhaps with the exception of pure ski boats.

When buying a boat, most buyers have to consider more options than your better half would find at a local Tupperware party and top of mind for most is the performance characteristics. I don’t simply mean top end speed. While this is an important consideration for some, you rarely get to go full noise, so the ability of the hull and motor to cope with water conditions is most critical. Three main areas buyers should look at are:

1) Softness of ride through chop
2) Cornering ability (without throwing the occupants out of the boat)
3) Stability at rest.

Aside from these elements, there follows a list, just as important, consisting of; what, where and how. Each category covers a multitude of questions;

What vehicle are you towing with? What modifications or inclusions am I likely to want? What will I do doing most of the time? What design elements are important to me? What will I need it to be able to do? What conditions am I likely to encounter a majority of the time?

The where’s cover; where will I keep the boat? Where will I launch? Where am I likely to use the boat? Where will I use it most of the time?

The final piece of the jigsaw is; how much money do I want to spend?

It is this critically important secondary list that really determines what sort of construction you will find most appropriate. As mentioned previously each has its own set of advantages which will become evident as you move through the process of boat ownership, or road test boats. Something I thoroughly recommend. When investing in a lifestyle such as boating, there is nothing worse than making a hasty and often regrettable decision. Get onboard boats of various constructions and get a feel for each ones’ capabilities. Within each build type different boats will also ride very differently, so don’t be afraid to road test and read reviews. It is a major financial commitment after all.

In order to really decide which type of construction is appropriate, let’s look at each in brief.

Aluminium is perhaps the most quintessentially Aussie of constructions. It would be a brave man that would challenge the rugged beauty of a tinnie as we affectionately call them. Aluminium is readily available here and is a hardy material that is relatively light. Construction methods can vary from rolled or stretched aluminium sheets commonly seen on sub 6m boats to plate construction usually reserved for larger offshore models. Both are strong build types with sheets welded together. Various thickness sheets are used but generally the thicker the sheet, the tougher the boat.

Boats built this way therefore have many benefits like toughness for weight, strength and easy maintenance. Runabout sized aluminium boats can be towed by a family sedan making the tow vehicle issue redundant and they are also cheaper than similar sized glass boats.

Aluminium constructions still allow variations in size and internal layout. You can buy an open boat, centre console, walk-around or standard runabout style in this material. They are also easy to add items to yourself and don’t require a degree in boat building to make minor modifications. Rod holders and electronics can be easily mounted by an owner with a little skill. In addition, console placement, seat placement, paint or no paint and hull thickness can be accommodated by most aluminium boat manufacturers too and plate aluminium has grown in popularity in recent years with its improved hull rigidity, quieter and softer ride coupled with better appearance.

Aluminium boats are also super tough and ideal for people using them in difficult terrain such as rocky shorelines, oyster racks and areas where you may bump structure with your boat on a regular basis. I fish and launch at an ocean ramp on the south coast which can experience quite a large surge and personally would not launch a big glass boat there so for me aluminium is the only solution. I can allow it to hit the ramp without being concerned that I am damaging the boat.

The limitations in the construction methods of aluminium boats mean that the hull angles cannot quite meet those that fibreglass produces. Therefore aluminium boats do not ride as well as fibreglass boats. In addition, aluminium is light and that can mean they can be pushed around by waves and water. On the plus side, an aluminium boat is often more manageable and much easier to look after and is a cheaper price point than equivalent sized fibreglass counterparts. So you can potentially get more boat in aluminium than fibreglass and indeed the starting point of aluminium boats are generally lower.

Fibreglass boats are a step above and no matter how you cut it, aluminium boats do not and simply cannot ride as well as a glass boat. Most reasonable quality glass boats rarely need to slow down for much and the weight and solid feel offered by fibreglass construction means the boat cuts through water rather than being pushed around by swell and waves. The end result is less slapping and more comfort due to the angles possible with glass hulls which are difficult to replicate with any other construction method. Any shape, angle or curve can be made with fibreglass construction.

For anyone who may potentially travel many miles to reach suitable fishing grounds but have the comfort of launching at a well looked after ramp free of heavy ocean surge, fibreglass would be natural choice. The comfort factor alone would enough to guarantee it’s on the list.

Fibreglass boats, like aluminium are also relatively easy to add electronics to as you can generally mount them directly onto any flat surface with self tapping stainless screws or stainless bolts (being careful to ensure there is nothing behind that can be damaged). Rod holders simply require a bit of common sense, a cordless and a hole saw. More elaborate changes in terms of layout options are a little less simple. As everything is generally moulded together, moving crucial items at the construction phase can upset the dynamics of a boat and result in poor or sub standard performance.

While the weight of glass boats is an advantage on the water, the weight often requires additional considerations on tow vehicles. At the large end of the fibreglass trailerboat range 4WDrives are common and indeed a necessity. Often glass boats can weigh considerably more than a like sized aluminium boat.

Damage is also a factor and glass boats can be easily damaged by misuse or mishaps. Fibreglass scratches and chips can occur on the hull so you certainly don’t want to be running you glass boat up onto rocks or a ramp as it will almost definitely end up with some damage. One added benefit of fibreglass is that unlike aliminium where you need specialized machinery to repair damage, fibreglass can be repaired with the use of a simple fibreglass repair kit consisting of matting, fibreglass, catalyst and sand paper.

Imagine you are fishing miles away from the nearest repair facility and you hole your boat. If you’re in an aluminium boat, getting to a suitable welder could be almost impossible and it’s unlikely you carry one around under the seat. Fibreglass on the other hand can be repaired on the spot with the kit. All you have to do is wait for the resin to harden and even a crude repair can get you back on the water or safely back to the ramp. This consideration is of particular importance for those travelling around the remote Australian outback with small car-topper type boats.

Plastic is relatively new as a construction method with Polycraft pioneering this build type. They are quiet, don’t slap and have good stability at rest. They are seemingly unsinkable, have incredible hull strength, almost to the point of being unbreakable and are surprisingly excellent boats. They are also relatively light weight, and require no maintenance except for a hose down after use.

The drawbacks include limited internal fit out options, interior comfort similar to aluminium and it does flex and move underneath you as it absorbs the uneven impact of the water.

So what do you look for in a boat? Everyone has a different list of needs and people value different performance characteristics. If you were to use a broad brush on the three construction materials you would say to buy Aluminium if you want a boat with less weight, plastic if you want a durable and functional all-rounder and fibreglass if you want on water performance, fit out and comfort.