The Bumfortable seat is designed to provide support to the bony structure of the paddler’s body, thereby giving good postural support from the seat base. Supporting the body from any higher can cause chaffing and muscular discomfort.
The majority of paddlers using a Bumfortable seat will find additional back support unnecessary. However, there is provision for a 25mm webbing strap to pass through a moulded tunnel around the top /back of the seat.
Attach this to the hull in front of the seat via some loops of cord fibreglassed to the hull, or by bolting with a small machine screw and nut under the coaming. A backstrap kit is available as an optional extra, it contains the webbing, buckles and stainless steel machine screws.
Bumfortable Back Strap has a few great advantages
You can use it to add extra back support. It has plenty of adjustment.
You don't need to glue the Bumfortable in so securely, as the backstrap significantly reduces the shear loading on the glue bond
The backstrap is a convenient way to hold the Bumfortable in position while testing it for correct trim and fit during initial installation, before gluing the Bumfortable in place.
If by chance the glue releases, you still have a fixing for the Bumfortable, and you won't lose the seat while driving with the boat on the roof.
In summary, for the extra few dollars, I recommend the backstrap as very worthwhile.