From what I understand, life jackets have been optional up to this point on Ride the Ducks tours.
I personally think a nationwide suspension of Ride the Ducks tours is an overblown reaction, even if it is voluntary. NBC News noted in their stories that the last serious accident was ten years ago in Arkansas at Hot Springs (The Hot Springs attraction NOT part of HFE.) Just my opinion here.
Let me relate a little story: When the FITH accident happened in 1980, it was handled quietly at the time. Most park guests were unaware anything was going on, and the rest of park operation continued normally. When Six Flags at St. Louis had a sky tram gondola car drop to the ground (about 1978) the park management freaked out and shut the whole park down. I know a sky lift car is more visible than an indoor roller coaster attraction, but I still think there is a good, quiet way to handle a problem, and an overblown, over reaction...my feeling is the nationwide suspension of Ride the Ducks is far too much. Again, just my opinion here. I don't mean to get anybody upset.