A saltwater trolling motor has to perform under fairly extreme conditions and so it is vital to choose one that will be capable of keeping your boat on course and not rot away.
The first consideration of any angler who is in the market for a new or used saltwater trolling motor is will it withstand the corrosive effect of the water, a fairly obvious concern but there are still many folks who will drop a freshwater motor in the sea and complain bitterly when it starts to rust.
When looking for your next motor ensure it is designed for the type of water you are going to be trolling in. A minimum requirement should be marine grade construction, this includes all parts of the motor from the prop up. The seals, joints and control all gear needs to be built for purpose, saltwater will get into anything that is not properly designed to cope with it.
Another factor to be aware of is the power output of your motor, tidal water is usually more dynamic than say a freshwater lake, this will put additional loads on the motor just to keep the boat moving forward in a straight line never mind steering against the ebb and flow of the currents.
A general bench mark for the power required for a trolling motor is 1lb of thrust for every 40lbs of load. The load is the total weight of your boat including everything that you have stowed on it, a safe option is to add the weight of the boat to the maximum payload and divide by 40, this will give you a minimum figure for the thrust required.
Once you have a figure for the thrust required the next step is to work out how long the shaft of the motor needs to be. This is affected by where you are going to have the motor, a bow mounted trolling motor will need a longer shaft than a transom mounted one. To get the length of shaft do a little bit of simple math, measure the distance from the mounting point on the boat to the water line, to this number add 15 inches (depth of the motor plus allowance for choppy water) and then about a foot to make it comfortable for steering whilst standing up.
If you have a saltwater trolling motor with a foot pedal the allowance for standing up can be ignored.
With the exception of engine mounted trolling motors it is always recommended to stow the unit if you are using another engine, say, an outboard. This is because your trolling motor will cause a drag effect thus wasting gas and also because the shaft of the trolling motor may break under the strain.
Any angler worth his salt (pun!) will have heard of the Minn Kota Riptide series. These great saltwater trolling motors are built for the job with enhanced marine engineering, corrosion proofing to defeat the saltwater and a patented composite shaft that has a lifetime guarantee against breakage, corrosion or kinking.
