Top tips for buying a seaworthy used boat

So you’ve decided to buy a secondhand trailer boat. Great! But now what?

On the market today there are thousands of used trailer boats for sale. There are good boats, bad boats, and in-between boats.

So how do you figure out what is a good quality boat, and what isn’t?

Nothing beats experience when shopping for a used boat, but newcomers can learn a few things to help separate the quality, seaworthy boats from the dogs, lemons and clunkers.

The first thing to consider when inspecting a potential boat purchase is whether the craft is likely to be seaworthy.

Factors like structural integrity and mechanical/engine condition are secondary at this point and can be considered once you have determined whether a boat is seaworthy enough for your intended boating or fishing application.

So what is seaworthiness? Well, seaworthiness is not any one thing. Pushed for a simple explanation, I’d say that a seaworthy boat is one that can be safely operated at sea.

The term ‘sea’ can refer to the ocean, the harbour, or an enclosed estuary, depending on what a particular craft is designed for.

Here are our top tips for staying afloat through what can be a bewildering purchasing process…

While many aspects of seaworthiness cannot be discerned by an examination of a boat sitting on its trailer, there are certain things to keep in mind.
Upon inspecting a boat, climb aboard and examine the freeboard in the cockpit and at the transom. What do we mean by freeboard? It’s the distance between the cockpit floor and the top of the gunwale. A craft designed to operate in coastal waters should have more than 600mm of freeboard.

The same applies for external freeboard. It stands to reason that a high-sided boat will be better able to keep water out than a craft that sits low down in the water.

Stability is another hallmark of a safe, seaworthy boat. To achieve good stability at rest, most alloy boats and smaller fibreglass boats will have a shallow or moderate deadrise hull.

If you stand at the stern of the boat you are inspecting, you will be able to examine the vee shape of the hull. Compare it to the diagram below. Do you think it has a shallow vee or a deep vee?

A shallow-vee monohull will likely be very stable but firm-riding.

A deep-vee hull bottom may be extra soft riding into the swell and the chop but it could also be a bit tender, or tippy, at rest.

A moderate transom vee hull is generally best for trailer boats up to about 5.5 metres in length, as this will provide the best compromise between ride comfort and stability.

Ride comfort will also be influenced by the shape of the bow and the forefoot. If the bow entry is very fine and sharply angled, then the boat is likely to be soft riding in choppy water.

Conversely, if the stem and forefoot looks flatter and more blunt, or the vee shape shallows rapidly moving aft, then you can expect the boat to be noisy and firm when riding at speed.

Pressed alloy boats usually have a flatter vee shape forward, and a shallow deadrise, which explains why they are generally harder-riding than a similar size fibreglass boat.

Having noted all of the above, a very fine bow entry shape can present a few problems. If the stem at the waterline is too sharp, and the stem shape is too vertical or ‘upright’, then this type of hull can slew or even broach in a following sea.

Of course, many other factors will contribute to and influence the ride, handling and seaworthiness of a boat including the shape and position of chines and running strakes.

It is rare for a long-established boat brand to produce a complete clunker of a boat. Most often the true dogs and lemons will come from a brand of boat you’ve never heard of.

The tip here is to shop for a boat from a well-respected manufacturer such as local boat makers Quintrex, Stacer, Haines Hunter, Cruise Craft, and Whittley.

Boating newcomers should also stay away from boats that have been modified.

You will come across boats with weird, unprofessional-looking modifications – including runabouts that have been converted into half cabins and boats that have been fitted with all manner of outboard engine pods.

These DIY-modified boats are an unknown quantity. They may work well, but you can’t count on it. The tip here is to simply stay away from them.

• Seaworthiness is determined by the shape of the bow, the angle of hull vee, the boat’s width, the shape of the ‘shoulders’, and a whole host of other factors.
• In craft more than 4.5 metres in length, look for a boat with cockpit freeboard where the gunwale rests against your thighs (more than 600mm).
• A monohull with a moderate/middle range vee angle will generally be a safe sea boat with good stability and a comfortable ride relative to boat size.
• Be wary of unknown boat brands and boats that have been modified from their original design, particularly if it has been repowered.

In theory, every boat that hits the water has to do so in a seaworthy state, which as we defined earlier, means it has to be in a good enough condition to travel safely wherever you take it.

However, Tasmania is the only state or territory in Australia to date that requires sellers to state that the vessel they are selling is seaworthy.

Under Tasmania's new rules introduced last year, both the boat's seller and the buyer must agree that the vessel being sold is ready to safely hit the water. If not, the boat's registration is removed.

The change to the way used boats are sold in Tasmania comes in the wake of a coronial inquiry into the 2016 death of four men who bought a boat and took it out to sea without checking its seaworthiness.

It is believed the boat's transom was rotted out and may have failed catastrophically. The boat had also been overpowered, using an outboard engine that did not suit the boat's original design.