Senator SST and XR
The difference between the Senator SST and the Senator XR is the open bow section. The open bow section is an available option which enables one or two passengers to ride in a seated bow compartment. The Senator SST (see above) does not come with the open bow compartment option but has a closed deck, whereas the Senator XR (click here for Senator XR gallery) comes with the open bow section. The advantage of the open bow section in the Senator XR is the ability to carry extra passengers in the bow; the disadvantage is that you lose a lot of the vast storage space the bow offers.