You have to modify the pedestal to lower the seat height since the Smooth Moves is higher to allow for compression. There is a floor mount you can replace the factory floor mount with that totally replaces the need to modify your pedestal. The spider is the part that attaches the pedestal to the seat. Smooth Moves is not a seat but a shock absorbing spring mount like farm tractors use between the seat and the pedestal.
In high horsepower boats the need for additonal comfort and passenger safety is necessary to get the full performance of your boat in rough conditions. The occasional ball jarring, kidney rupturing or literally back breaking waves can ruin a trip or a summer. Smooth Moves take the sting out of potential injury.
If you have ever been in 30 MPH winds with a 20 mile run to complete in 30 minutes you’ll apreciate on. If you have a boat under 100 HP you don’t need one. Boats under 17 feet probably cannot handle the additional weight either.
Tournament fisherman and those of use who fish everyday for a living in all kinds of conditions appreciate the ride in their Smooth Moves or eqivilant at the end of the day.