Narrowboat Surveys explained

When the sale price has been agreed on a narrowboat, 99% of the time a boat survey will be undertaken. The survey is completed on behalf of the purchaser, by their chosen surveyor.

The Survey

When the surveyor comes to assess the narrow boat, they check all the Internal systems & the hull (steel thickness) and produce a report, the report usually takes a week to produce, although if the buyer can be present on the day, they can usually be given a verbal report.  

This photograph shows how a surveyor prepares the narrowboat to measure the thickness of the hull using an Ultrasonic meter. They also use a hammer to assess the condition of the steel. If they discover the hull is in need of refurbishment, the works would have to be completed to bring the hull to an insurable condition.

Example of a Hull Survey

For example, and for ease of use, I have chosen to say that this "narrowboat" is in need of overplating the base plate.

The boat would be craned out of the water for preparation to begin. The lip of the original base plate will be cleaned so that a good quality weld is achieved.

When the preparation has been completed, the steel would have arrived, it will have been measured. ordered and cut to the correct length and width.  Either a forklift or bottle jacks would be used to raise the plate under the boat. Once the steel has been aligned it will be tack welded to hold it in place, as in the photo beneath. Small squares will be cut out of the center of the new plate, to be able to weld the new plate to the original base plate. These squares are then welded back on.

In this photo you can see the welds that are approximately an inch long. If you look carefully you can see the original base plate lip has been cleaned and is now a silver colour. Once that has been tacked into place, the welder will start to fully weld the plate.

The type of welding used is Arc welding, this is one of the strongest forms of welding and is the preferred type on narrowboats. It's better in this environment because it doesn't require any gases, it performs better outdoors and in the elements.  Ideally for the best possible penetration for a weld, a slight gap should be left between the plates (the gap size varies on the size of the welding rod) with a slight angle on the lip of the joining plates, creating a V - shape.

This is a photo of a continuous weld, as you can see it has just stopped on the tacked weld. It will continue around the narrowboat until it has been fully welded.  Once it has been fully welded the excess on the bow and stern will be cut off.


If anodes are required these would be fitted too.

Survey Findings

If the surveyor finds any narrowboat safety items that are dangerous, these will have to be rectified for the safety of the user.

Once we have received a copy of the survey report, we then price the work that is compulsory i.e. boat safety items, steel work and any other items that are for insurance purposes. Once we have an estimate to send to the client we give the vendor an update on the situation of the sale.

When a price has been agreed by both parties and the boat has been paid for, the repair/refurbishment work can commence. The purchaser will be given a start date and an approximation of how long the work will take to complete.


Re Inspection

The Surveyor will then return to inspect the work that has been done, and check it has been completed to the correct standard. They will then issue a certificate to confirm this. The narrow boat's hull will then be blacked in bitumen or other suitable paint. Once the paint has dried the narrowboat will be refloated in the water, where it will await collection by it's new owner, now with a new lease of life.