This is very much a matter of compromise. You will want the biggest boat you can for comfort, seaworthiness and load carrying. But you need it to be small and light enough to load and carry. Typical roof toppers
are between 3 m and 3.7 m and weigh between 60 and 80 KG. But with the right set up, many people carry boats up to 4 m in length and 90 KG or more in weight. Factors to consider in deciding on boat size include number of people, the equipment you want to carry, how you will load it and the size and weight restrictions imposed by your vehicle.
Will you use your boat in small creeks and calm water or larger water expanses like estuaries and large dams? The hull type you choose should be based on the planned use of the boat. Flat bottom punts are very stable at rest, but are only safe in calm water. A deep V is more suited to choppy conditions. Remember, even ‘sheltered’ water can quickly become choppy if a wind comes up. The V also gives you a smoother, more comfortable ride across any waves or chop and keeps you much dryer. Some companies combine these designs in a V Nose Punt, but remember, while a flat bottom is very stable in calm water, they are quite unsuited to choppy or rough conditions.
Deep V style boats also typically have higher sides than punts. While this makes them a little heavier, it may make you feel a little more secure if fishing in the North of Australia
where saltwater crocodiles are common.
Generally the gunwales of a roof topper need to be fairly flat and unobstructed by side rails, rod holders or any other protrusions which may prevent easy loading onto carry rack.
A boat loader is just that, a device that assists in loading a boat on the top of a 4WD. This purpose built roof rack usually incorporates a winch-like pulley system that’s used to raise the boat into position. When considering a boat loader, you must take into account not just the roof carrying capacity of the vehicle, but also the strength of the type of mounting to cope with the sheering action when the boat is lifted from horizontal position. The ropes need to be strong enough with roughly 750kg breaking strain yachting ropes on the front and 550kg breaking strain ropes on the stern. There has been some discussion, that winching from or attaching a boat to an airbag compatible bull bar may invalidate warranty on an airbag system. Now although you should look into this further, there are manufacturers that support good compliance such as those that use ropes that lock the boat down to the rack and also attach ropes over the front of the boat via holes in the frame/outriggers specifically for this purpose.