Jugs of water in the boat (more volume than the tires) to be emptied once you've launched and are in the boat.

Laszlo

You might need to attach the milk or gallon jugs to the trailer frame because once the boat if off the trailer the trailer will float even higher and it might be difficult to load the boat. The added weight to the trailer can keep the tariler on the boat ramp and as low as possible so loading the boat at the end of the sail will be as easy as floating the boat over the sumberged trailer. When traveling on can empty to jugs for the lightes load or keep them full if one needs a heavier load for a little more stability.

I don't believe milk jugs would work. If they are in the boat, they will keep the boat from lifting off the dolly. If they are on the dolly they would just be neutrally buoyant in the water. I would have to add weight such as lead to the trailer itself, but then the trailer would be a pain to move around.

���You could also ballast the tires by filling them with water. Look up tractor tire ballasting. Farmers do it all the time. If you leave it outdoors in freezing weather use antifreeze.

Water ballast in the wheels on a hand dolly?  Not if I have to lift it.

1. You could just get replacement wheels. 

2.  If these plastic beach floatation wheels are what I think they are they are not pressurized and don't carry a lot of weight.   Perhaps you could just drill some holes in the wheels and let them fill and conversely drain.  

I think your right that replacement tires would be the only help. The Sand tiers I purchased are nice pneumatic tiers. Drilling hole would be a bad thing, same as filling with water, or adding weight of any kind.

 Mikeflys -

I launch my Skerry from a Davis cart, not a Trailex dolly, and I also had flotation problems.  I replaced the wheels on my cart with a couple of Marathon Flat-Free tires that I purchased from a big box store.  The cart still has a little buoyancy, but not much – it's made an unmanageable situation very manageable.  You might check the Marathon website (www.marathonind.com) – Marathon will sell direct - to see if anything suits the Trailex cart.

In my case I had to jury-rig adapters to make the wheels fit the axles, as the cart axle was larger in diameter than either of the bearings supplied with the wheels.  Instead or rolling element bearings I ended up with sleeve bearings fashioned from a length of PVC pipe slathered with grease on the ID.  I'm now in my third year with this arrangement.

hokker

   I like that idea. I checked the website and those tires are $50 each. That's too much for me as an experiment. But I checked good ol Harbour Freight and they have cheep Chinese knock offs for $7 each. I can afford that, even if they only last a season it would prove it would work. I could upgrade later. I just have to find out if the hubs will fit.

Its a 100# seventeen foot boat. One might ask the question why does the dolly have to be in the water?  I've launched a lot of    loaded canoes and kayaks at 17 ft that weighed more than 100# and never got the dolly in the water.

   Grumpy that's an easy question to answer. I don't want to drag my boat across the cement of the ramps. As I said I hadn't yet found a beach to launch from.