Looking for some opinions about floating boat lifts. Due to muddy bottom conditions I think that a traditional lift is out of the question. I have an idea of building a lift as all the parts are available and I don’t see an off the shelf lift working with the amount of water in the cove I dock it.
my plan is to basically copy my trailer design within a rectangle frame and use two ballast tanks towards the rear. This would be attached to a pivot just above water level and be attached to a floating dock system. Concept would be similar to pulling onto a trailer. Fill tanks with water to drop the rear of the lift into to water, air up to lift the boat.

I do not have any floating lifts on the lake to view so I have a few questions.
Are there any valves that ensure that the lift goes up in a somewhat level orientation?
do the tanks just get plumbed with a tee fitting from the pump?
If water level is an issue could the tanks be mounted outboard of the lift frame to ensure the frame goes deep enough?

Main reason for the boat to be on a lift is to reduce lake scum on the hull and also keep the boat dry as possible. In theory the boat would only be lifted about a foot out of the water. likely have a u shaped dock around the boat.

boat is a 24ft Baja

Am I crazy for wanting to try this?

Boat Lifts - FloatAir Boatlifts - 4 Corner, Front Mount, and Side Mount
Check out the link. I own a 6000 lb Float Air boat lift that is fastened to the front of my floating dock and it drops down as you described. The tanks are full width and mine has 3 of them. Since they are full width you don't worry about one side going up faster than the other. Mine has the blower connected to a 3 way ball valve. One position for storage, one to lower it that lets the air out of all 3 tanks at once without any power, and another to raise the lift that requires you turn on the blower motor to displace the water and fill the tanks. The hose goes to and connects all 3 tanks so they usually fill at the same rate or very close to the same rate. I don't think there are any valves besides the ball control valve. I believe there is an exhaust port (not sure of the diameter) on the bottom of each tank. When you open the valve to lower the lift the water enters the exhaust port and fills the tanks. When you raise the lift, the air enters the tanks via a hose from the ball valve to the first tank and from that T fitting to the 2nd tank and from that T fitting to the 3rd tank. When you fill the tanks with air to raise, if you keep adding air eventually bubbles come up from the exhaust ports if you put enough air to completely fill the tank. In my case that would bend the lift a bit.

How much water depth do you have?? The type of lift you are describing puts a lot of stress on your dock, especially if there is any wave action. Lifts and docks at LOTO are nearly 100% floating type lifts and the kind you are describing is 1 in a 1000 and no marinas or condo docks allow them. The way floating lifts work is that air gets pumped into the tanks and the pressure forces the water out through a hole in the bottom of the tanks. The same types of lifts are used in our river marinas in the Omaha area.

Check out Poly Lift, Galva Lift, LOTO lift, Fibersteel boat lifts

In the mid west we always used floating lifts, but down here the water is to shallow for them. The 4 post or boat house lifts by Boat lift US or Deco (just to name a few) are used. At my place I have the bunks set so the keel of the boat just clears the I beams, this means I can lift the boat even with only 3 feet of water.

No floating lift would work at that level.
https://www.boatliftus.com/
https://decoboatlift.com/
https://tidewaterboatlifts.com/

fibersteel front mounted lift

Depends on how deep the water is.

The back of my lift (it is about 24 ft long) drops around 3.5 ft into the lake when it is all the way down. So it would work in as little as 4 ft water depth (at the back of the lift) or slightly less. I live on Lake Keowee, SC and 99% of the docks on this lake are floating docks and almost all of them are equipped with floating boat lifts. Not sure what percentage of them are front mount, perhaps 30%??

I probably have an average of 4.5 feet of water during the boating season. I looked at float air lifts but was unsure about water depth. I would be doing this the same time as a new dock. I could to a front mount or ever a 4 corner mount.

im about 90% sure that any lift that I put on the lake bottom would sink out of sight once a boat is lifted. Even if I were able to stop it sinking I don’t think I would ever get it out in the fall.

but the way that things are going I may not even have a drive for the boat this summer. Unless mercury gets their ass in gear and makes some damn gear sets.

Could do what we did….

contact jet dock systems check out their site, i love mine. this is not my boat but just an example

Float lift 2 years old with automatic remote cover and remote lift. Sold our Super Air Natique. 26’ boat