"Many good Fiberglass Hulls display water ingress. 60% of boats over 20 years old will have developed blisters...
Whether you are a first time boat owner or experienced mariner, insurance companies and lenders would like to see you do your part in reducing risk and minimizing loss: 1. Inspect or have your boat inspected by a qualified mechanic ideally twice a year or immediately upon the advice of your surveyor. 2. Repair and replace any defective equipment properly as recommended by your surveyor. 3. Install theft prevention devices on all electronics, engines, outdrives, and trailer hitches. 4. Install alarm systems on your boat for high bilge water levels and cabin intrusion, theft, fire, smoke. 5. Always follow responsible safe boating practices, PFDs, Rules of The Road, Speed Limits, No Wake Zones, and Safe Refueling Practices. 6. Above all else, use common sense on the water. Do not put your life or your property in harms way. Keep advised of adverse or deteriorating weather conditions. Always be certain your vessel, crew, course, and safety gear are seaworthy for a particular voyage, before leaving the dock.
Tips for "Looking Over" a Boat (A diligent practice but no substitute for a professional)
1. Indicators of previous sinking include: Mud, dirt, sand in tight spaces and bilges. Check spaces where decks join hull and hidden bulkheads. Always review a boat’s history.
2. Bad Wiring: corroded wires, burnt ends, hastily reapplied ends can indicate fire damaged or previously submerged wire. Wiring should visually display some methodical and neatly organized routing. Beware of anything that looks like it is about to short circuit or burn down the entire Marina (it pry will). Always look at terminals where panels and wire ends.
3. Excessive Mold and Mildew: indicates previous sinkage, partial sinkage, long term storage or simply poor housekeeping and neglect.
4. Cracks in Hull: Should be evaluated carefully especially when displayed in critical areas of the hull: beneath engine stringers, at bow, encircling rudder, post or propeller shaft.
5. Engine: Look for excessive rust, remove oil filter, inspect as far as you can see to and past rocker arms. Dirty? Rusty? Sludge Build Up? Have a mirror affixed to a long wand to look under, behind the engine for rust, oil leaks, etc. Always procure a mechanic to conduct a full diagnostic engine survey. Your surveyor likely does NOT have this expertise, and it is well worth the added expense.
6. Wet Hulls: A moisture meter by itself does not indicate a wet hull. Tap (lightly) on the hull with you fingers or plastic hammer. Most dry hulls will produce a clean sharp "click" with no bounce back. A wet hull will produce a dull "thud" with no bounce back. A delaminated hull will produce a lighter pitched "click" with bounce back. Be aware a "perceivably" dry hull can be just as deceptive.
7. Blisters: Many good used boats will have some blistering. Some boats had factory recalls especially during the 1980s. Check the USCG website for factory recalls for the past 25 years. Some great boats will have some blistering problems that can be readily fixed with time and money. Use your inspection judgment. Approximately 30% of boats under 10 years old will have some blistering. Approximately 60% of boats over 20 years old will have some blistering. Contrary to any myths, water ingress does not typically add extraordinary weight to a vessel's displacement. Maybe 4% - 5% depending.
8. Fuel Tanks: See engine above and use a wand or mirror to check as far as possible over under and around the tanks. Iron fuel tanks are common in older boats (beware). Properly installed Aluminum or Fiberglass tanks are preferred. Check for water under the tanks. Use a clean rag to wipe all over the tank, under and around the bilge (especially the corners). If you see fuel or oil on the rag, be cautionary and request the tank be lifted for further inspection or possible replacement. The same diligence is necessary with fiberglass tanks because of the ethanol creep.
9. Deck and Topside: When water enters the sandwich through screws, bolt holes or flaws, serious problems arise. Check for discolored paneling, flooring, painting. Port holes, hatches, doors, gangways with water stains or filtering may indicate past problems.
Expected Cost of Ownership So much of a surveyor’s responsibility is tied to not only protecting your safety and vessel soundness on the water, but also your financial interest. Quite often new owners believe the cost of ownership is much lower than it actually is. Don’t be surprised when you start filling those small cracks in the deck with $100 bills. According to David Pascoe, one well-respected member of the marine surveying community (now retired), the average annual cost of ownership (not including lien or boat loan payments) is as follows:
Vessel Age / Annual Upkeep (Percentage of Purchase Price)
1 -5 Years 8%
5-10 Years 12%
10-15 Years 15%
16-25 Years 18%
Based on the above matrix, a 25 year old 40’ boat priced at $50,000 (which sold for $350,000 new), may not be such a great deal. Annual cost of ownership (upkeep alone) would likely be $9000, plus any bank loan used to finance ownership of that vessel. These projected costs of ownership are average at best, and variance in either direction would not be entirely uncommon. The numbers should not dissuade anyone from purchasing a used boat, buying new can be just as painful. Many pre-loved boats on the market do in-fact represent a great value if inspected properly.
Cautionary words about bilge pumps Bilge pumps can give off a false sense of security. Most are wired with a 3 position switch ON, OFF and AUTOMATIC. When set to AUTOMATIC, the pump is activated by a float switch that turns on when water level in the bilge lifts it to the ON position, then OFF when the water level recedes (this is when everything is working properly). However, float switches commonly get stuck in the ON position and not shut off. The result is draining of the boat's battery that can easily result in sinking. Unfortunately, bilge pumps are sometimes selected on price vs. "head." Head being defined as the specification of how high the pump will lift water to discharge it from the bilge. Volume is how many gallons per hour the pump can discharge on a continuous basis. Because the two terms are inter-related one can imagine the pump will NOT always discharge at the manufacturer's rated "volume." On a powerboat, it is unusual for a pump to have to lift water more than a couple feet, compared to 4 or 5 feet on a deep keeled cruising sailboat (which will significantly reduce the manufacturers rated gallons per hour). Author Dan Spurr points out in his book Upgrading the Cruising Sailboat that a one and one half inch hole two feet below the water line will admit 71 gallons of water per minute! That's 4,260 gallons an hour! This figure exceeds the pumping output of the largest available electric bilge pump operating with little or no head and fully charged battery. ABYC's H-22 Standards for Bilge Pumps is limited, simply indicating bilge pumps are intended for control of spray, rain water, and normal accumulation of water due to seepage and spillage. Hence, Boat Builders are installing pumps to address such and only such standard. Because of this, it is highly advised every mariner always carry a manual diaphragm pump which can at least provide a fighting chance against the inflow of water in an emergency. The ideal number of pumps would be anywhere between 2 and 5, depending on the size of the vessel (16ft - 60ft) and capacity would range anywhere from 2500 Gallons Per Hour (GPH) to 10000 Gallons Per Hour as vessel size increases.
Longevity of Fiberglass Hulls and Blistering The facts of science and chemistry is that Steel, Aluminum and Wood all require constant maintenance, which, if neglected would have far more severe effects on structural integrity over a shorter time period. A fiberglass boat will likely withstand prolonged neglect without the hull being weakened. Ingress of moisture (which can lead to blistering) occurs over years and in the end, might not even result in the formation of a blister (or chemical change in properties of the GRP matrix).
How to help prevent osmosis and reduce potential for Blistering Typically when buying a new boat, it would be advantageous to ask what kind of resin was used in construction of the hull. Isophtalic or ISO is best, compared with Orthophtalic. History has shown hulls laid-up using ISO resin are somewhat more blister resistant. If the hull was not laid-up with ISO resin, then an application of 3 – 4 coats of solvent free epoxy paint might be the next best line of defense (making sure the hull is dried out and prepped properly before application). When buying a pre-owned boat, again, ask what resin was used in the lay-up matrix (ISO or ORTHO). It is entirely possible this information is unknown, and in such case, moisture levels in the hull will provide an indication how effective the gel coat and laminate system have prevented water ingress over the years. If the prior owner has applied a protective epoxy coating to the boat find out if it was solvent free and who did the work – the owner himself, or a qualified marine technician? It is also useful to know if such an application was done to protect against blistering or treatment after blistering. When owning a boat, considering all lay-up methods or osmosis protection is perfect, osmosis can be further prevented by avoiding fresh or warm waters. Although it seems counter intuitive, fresh and warm water will enable osmosis and blistering. Metal Corrosion is another story.... fresh water is usually easier on a boat, slowing down that type of problem. However, salt water is easier on a boat with regard to preventing water ingress. A quick lesson in physics and chemistry would demonstrate that Fresh and Warm Water are of much lower density and therefore exert greater hydraulic pressure on the underwater portion of a hull, causing water molecules to permeate easier. Warm water also softens gel coat, resulting in fiberglass being more permeable. Helpful Links