Understanding Boat Hull Materials
Oct 13, 2000
Just about anyone who owns a powerboat has a boat that is built out of fiberglass. Many modern sailboats are built out of fiberglass. There are some alternatives out there, such as aluminum, inflatable, rigid inflatable, Roplene, carbon fiber, Kevlar and wood hulled boats (not all encompassing). Understanding these materials will help you make a buying decision that will match your needs, aesthetic sensibilities and pocketbook. Let's take a look at each.
Wood: Many older boats feature wood hulls. Many newer boats feature wood components in their hulls. Wood has been used in ship/boat building for many centuries. Wood is solid and offers good flotation, but poor rot resistance. The key to dealing with wood and wooden components is knowledge. If your boat is a wooden hulled boat, such as a vintage Chris Craft, you probably know that. If you own a newer bowrider, you may be surprised to find out how much wood is used in its construction. If you want a low maintenance hull, you may select a boat that features "no wood construction", like an Edgewater or many others. If your boat or prospective boat has some wood in its construction, know where it is, and take due care to ensure it remains rot free. Inspect often, and keep it clean and dry while storing. Wood is strong, flexible and viable, but due care must be exercised. Wood can rot, retain water and subsequent weight, and can cause headaches, especially if the wood is hidden. Know your boat.
Aluminum: There are some excellent aluminum hulled boats on the market, but generally with specific applications. Flat bottomed aluminum skiffs, especially those used in fresh water, fare very well. V-hulled aluminum fishing boats seem very popular in the great lakes and in other large inland freshwater areas. Aluminum boats almost never offer luxury amenities, and are generally used for fishing/utility. Aluminum is very rot resistant, but it can corrode, and riveted boats can leak, especially older models. Aluminum offers a good strength to weight ratio, and you may see aluminum boats with smaller engines that feature good performance and economy. Aluminum boats may pound in heavier seas, and those that feature wood components must be inspected and maintained properly. Aluminum boats are loud compared to other boats built with more sound deadening materials. Aluminum hulled boats are best for basic utility uses, those that reach the fiberglass performance/comfort level are not economically advantageous over the fiberglass hulled boat.
Fiberglass: Fiberglass hulled boats vary wildly in design and construction. Fiberglass is an extremely popular hull material. Fiberglass construction is hand labor intensive, so quality can vary somewhat from example to example. Many newer fiberglass boats are self-bailing/unsinkable with foam injected decks and topsides. Fiberglass is very rot resistant, and can be extremely strong, depending on design features. Many newer designs that use fiberglass also incorporate wood, but they use encapsulation, a method of construction that shields the wood from exposure to the elements. Fiberglass can be a heavy material, but added weight may enhance the sea-worthiness of a given boat design. Some automation of late has added to fiberglass quality control. An important factor concerning fiberglass boats is that of their gel-coat, or top coat. A good quality gel-coat will withstand more abuse than a mediocre gel-coat, and this pays off in hours spent in maintenance activities. Gel-coat generally requires waxing and careful maintenance. Fiberglass can also be molded into various shapes that allows for anchor lockers, fish boxes, battery boxes, and storage to be molded into the deck of the boat. Fiberglass is a very popular boat building material.
Carbon Fiber/Kevlar: Some companies, especially those that produce the relatively new "flats boat", and inland saltwater fishing boats use these space age materials to fulfill their designs of light weight and shallow draft. Boats designed to fish shallow water need these qualities, but at the same time need sufficient beam to offer stability for the angler who may need to move around on his boat's deck. The power needed to move these esoteric boats is also reduced, with a corresponding weight savings in engine size and necessary fuel on board. Boats built from these materials tend to be very expensive and somewhat light duty in my opinion. Yes, the materials are extremely strong but the material seems tentative. I would hate to whack one of these things into a dock post for fear of cracking it. Needless to say, this hull material is very specialized and very expensive.
Roplene: At least one company out there (Logic Marine) is building boats out of plastic. Their first boats were inflatable appearing boats that featured full plastic construction. Their boats are roto-molded, a process that adds plastic to a rotating mold, after a while the molecules all gel together and you get a boat hull. Folks familiar with fiberglass may not like the fit and finish of these boats, but they are produced with utility in mind. They weigh in the ballbark of a fiberglass counterpart, but they have no delicate gel-coat to craze or crack, and they don't have any color or paint to fade and degrade. They are not fancy, and the price is right. One problem they do have is that of holding hardware. It seems the inherent flex of these plastic hulls may allow for the backing out of deck screws and the like. It is a design problem I'm sure this young company will solve. Advantages? You can beach these boats without worry, and they simply will not rot. Did I mention price? These Roplene hulled boats won't please everyone, but if you just have to float, you plan on beaching the boat on oyster bars, and you don't have scads of money, look at one of these.
Inflatable/Ridid Inflatable: These specialized boats are built with one quality in mind; ruggedness. Inflatables will handle impressive seas, although they will pitch and roll, and the power applied to the transom is limited in this regard. Rigid inflatables, on the other hand, are the Godzilla of small boats. Their rigid V hulls with inflatable tube surround (or floating tube surround, as in the Safe-T-Boat example) are absolutely sea worthy. They are used by military, Coast Guard, police and rescue workers everyday. They are also very expensive. Many can take lots of horsepower, and most are utility minded machines. I have seen a couple of industry front runners that market these types of boats to the recreational set, even fisherman. Most of the rubber surround bladders are compartmentalized and of low pressure, so puncturing the bladder with a fishhook is not a big deal. The problem with these boats for the recreational boater is cost and limited cockpit space, most will opt for a more useful and economical fiberglass boat. There are a few moneyed folks out there that will run a RIB for their excellent qualities, and perhaps for their penchant to be just a little bit different than everyone else.
There you have it. There are many different hull materials to choose from out there, you only have to decide which fits your situation and expectations. Certainly the time and effort spent by the manufacturer in its construction of your prospective boat will weigh heavily on your purchase choice, perhaps more so than hull material. Take your time, become an expert on boats, and then make the kill at your dealership. Above all else, test drive your prospective boat! This will tell you the volumes that you need to know about your prospect when it comes time to get serious. Do your homework and make the right choice for you, because chances are, you will be living with your decision for a while!