+1.
Given the limited information we have; Dual axles suggest it is between 4000 and 8000 lbs.
There is a lot of give and take in that range. So i'll guess 6000#, Plus or Minus 3000#.
Get it weighed and then you'll know. Weighing cost less than $10 and can commonly be done for Free with very little research.
Pontoons aren't that heavy. Tandem axle pontoon trailers are common, not because of the axle requirements, but because of the tiny tires and the stability requirement of pulling a billboard through the wind. My last pontoon tipped the scales at just over 2000 pounds, and came from the factory on a tandem.
Anyway, looked it up, and it looks like the largest pontoon voyager made that year was a 26 footer. Weight on that was 2500 pounds without motor, so add another 500 for fuel, motor, battery, some life jackets. Add another 770# for the trailer, so a fairly accurate rough guess pus you at 3770#