The two most important considerations when choosing a kayak trailer are how the trailer will be towed and how the kayaks will be stored. Towing the kayak trailer on the road means the unit will need to be street-legal; this usually means the tires, wheels, and axle need to be a certain size, and the unit will need to have working brake lights. The construction of the trailer might also need to meet certain specifications in terms of size, durability, and other dimensions.
Other kayak trailer designs exist. A kayaker may, for example, be able to buy a very simple hand cart for moving the kayak over short distances. Such carts are useful for loading a kayak into the water after taking it out of storage in a garage or boat house. Some kayak trailer models can be attached to a bicycle so the user can tow the kayak by bicycle to a launch point at a body of water. Such a trailer will not need to be street-legal, though it will help to buy one that is stable, sturdy, and easy to attach and detach from the bicycle. If the trailer will be used off-road, on dirt paths, or on roads that are not well maintained, the wheels should be made from strong materials, the tires should be wider than usual, and the axle should be durable enough to handle the stress.
If the buyer intends to hook the kayak trailer up to a vehicle for towing on-road, the first decision he or she will need to make is how many kayaks will be towed at one time on the rig. Some trailers are designed specifically for one kayak only, while others may be able to handle four or more kayaks. The buyer should think about how many boats he or she is likely to haul at full capacity to figure out which model will be best for him or her. The slots in which the boats will be secured should be padded, carpeted, or otherwise protected to prevent scratching and damage to the boats.
The buyer should consider the weight of the kayak trailer as well before purchasing. Heavier trailers may not be suitable for smaller cars or those with smaller engines, and even if the vehicle is rated to tow a heavier trailer, the buyer needs to remember that a heavier trailer means worse gas mileage. A lightweight trailer can help save on gas, but it is important to consider strength as well, especially if the trailer will be hauling several kayaks at once.