Pontoon Boat Lifts: Getting the Tubes, Weight and Bunks Right
Quick answer
A pontoon boat lift supports the boat under its tubes, not a V-hull, so it needs long, correctly spaced bunks or tube-specific cradles. Most pontoons and tritoons need a lift rated about 3,500 to 7,000 lb once engine, fuel and gear are counted, and tritoons often need a center bunk because much of the engine weight sits on the center tube.
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Pontoon boats are the most common family boat on many inland lakes, and they are also the boats most often put on the wrong lift. A pontoon has no keel, no V-hull and no chines to rest on. Its weight is carried by two or three long aluminum tubes, and the deck sits 2 ft or more above the water with a large flat surface that catches wind. Those differences change how the lift supports the boat, how it should be sized, and what goes wrong.
How a pontoon sits on a lift
On a V-hull boat, bunks follow the hull and the keel helps center it. On a pontoon, the tubes must rest on bunks running lengthwise directly under or alongside each tube. There are three common approaches:
- Flat bunks under the tubes: long bunks positioned directly beneath each tube. Simple, but the round tube touches the bunk along a narrow line, so the bunk must be wide and padded.
- Cradle bunks or V-bunks that cup each tube: two bunks per tube, angled to form a saddle. They center the boat, spread the load across more of the tube, and are common in pontoon-specific lift kits.
- Bunks between the tubes: some designs support the boat at the inner sides of the outer tubes or under the crossmembers. This is less common and depends heavily on the boat's construction, so check with the boat builder.
Whatever the style, the bunks must be long enough. A 22 to 25 ft pontoon has tubes nearly that long, and short bunks concentrate the load near the cradle beams, which can dent tubes or stress the brackets that tie tubes to the deck. Most pontoon lift kits use bunks in the range of 14 to 20 ft or more, depending on boat length. See bunks and cradles.
The tritoon center tube
Tritoons (three tubes) put the outboard on a bracket at the stern, often centered over the middle tube. On many tritoons the center tube is also larger or has an under-deck lifting strake. The result is that a large share of the engine and fuel weight bears on the center tube near the stern. A lift that supports only the outer tubes leaves that weight to be carried through the deck structure, which is not what it was designed for at rest. Many tritoon lift kits add a center bunk, or a center support near the stern, for this reason.
Worked example: sizing a lift for a 24 ft tritoon
Assumptions: 24 ft tritoon with a published hull weight of 3,100 lb without engine, a 250 hp outboard at about 550 lb, 40 gal fuel tank, two batteries, a typical family gear load, and a bimini top.
- Hull and deck: 3,100 lb
- Outboard: 550 lb
- Fuel: 40 gal x 6.1 = 244 lb
- Batteries: 2 x 60 = 120 lb
- Gear: coolers, tubes, life jackets, anchor, cushions: 400 lb
- Loaded weight: 4,414 lb
- With 15 to 25% margin: 5,076 to 5,518 lb
A lift rated about 5,500 to 6,000 lb is the sensible choice. A 4,500 lb lift, which might look adequate against the brochure hull weight, would be overloaded.
Load on the tubes: suppose the engine, fuel and batteries (914 lb) sit mostly over the stern of the center tube, and the rest (3,500 lb) is shared roughly evenly across the three tubes. The center tube then carries about 3,500 / 3 + 914 x 0.7 = 1,167 + 640 = about 1,800 lb, while each outer tube carries about 1,167 + 137 = about 1,300 lb. That is roughly 40% more on the center tube than on either outer tube, concentrated toward the stern. A lift that supports only the outer tubes would have to carry the center tube's share through the deck and crossmembers.
Pontoon weights vary widely by length, tube count, tube diameter and options. Use the boat weight database and the capacity calculator for your specific boat.
Which lift types work for pontoons
| Lift type | Fit for pontoons | Notes |
|---|---|---|
| Free-standing vertical (lake-bottom) | Very common on inland lakes | Pontoon bunk kits widely available; removable in ice country |
| Free-standing cantilever | Light pontoons only | Capacity and width limits rule out most larger tritoons |
| 4-post piling vertical | Good for permanent docks and larger tritoons | Top beams must clear bimini and any enclosure |
| Floating hydraulic or air lift | Good on fluctuating reservoirs and tidal water | Wide pontoons need a wide, stable platform |
| Beamless hydraulic | Works with appropriate cradle | No overhead beam to conflict with tops |
| Elevator or davit | Rarely suitable | Wide beam and deck structure do not suit wall or two-point lifting |
Free-standing lifts from ShoreStation and ShoreMaster are common sights under pontoons on northern lakes, typically with pontoon-specific bunk kits. Floating lifts from makers such as HydroHoist and Sunstream are used where water levels swing. See free-standing boat lifts and floating boat lifts.
Width, slip and depth
Most pontoons run about 8 to 8.5 ft wide, the practical trailering limit. The lift's inside width between legs or pilings must fit the boat with clearance for wind while loading, often 1 to 2 ft on each side. Longer tritoons may also need a longer lift frame or extended bunks so the stern overhang does not exceed what the builder allows.
Depth is usually easier than with V-hulls. Pontoons draft roughly 1 to 2 ft depending on tube size and load, so they float onto lifts in shallower water. The catch is the outboard: it is the deepest point, and in shallow water the skeg can strike the bottom or the lift frame when the cradle is lowered. Trim the engine up before driving on. Check depths with the water depth calculator and read water depth requirements.
Wind: the pontoon's hidden load
A raised pontoon presents a broad side to the wind: tubes, fencing, bimini and sometimes a full enclosure. That surface acts like a sail, pushing the lift sideways at its top. A free-standing lift resists this only through its leg geometry and weight on the bottom, so a raised pontoon on a light frame in a strong storm can rack or tip the lift.
- Lower the bimini and remove enclosures when the boat will sit on the lift through windy weather.
- Use the lift maker's tie-down or anchoring kit on free-standing lifts in exposed water.
- Do not raise the boat higher than needed; extra height increases the leverage of wind on the frame.
- Canopies add their own wind load. If you add a lift canopy, confirm the lift is rated for it. See boat lift canopies.
Regional differences
Northern freshwater lakes: free-standing vertical lifts with pontoon kits dominate. They come out each fall in ice country, so the lift must be light enough for the dock service to remove. Pontoons are often removed to storage, but some owners leave them on the lift under cover while the lift stays in, which only works where the lift is out of the ice path. See winterizing a boat lift.
Southern reservoirs: water levels can swing many feet with drawdowns. Floating lifts or lifts with long travel make sense, and a free-standing lift may need repositioning several times a season.
Coastal and tidal water: aluminum tubes and saltwater mean galvanic corrosion is a real concern, especially where stainless or steel hardware touches the tubes or where shore power is miswired. Lift hardware touching the tubes should not create dissimilar-metal contact, and bunks should isolate the tubes from steel parts. See corrosion protection.
Failure modes and their causes
| Problem | Cause | Prevention |
|---|---|---|
| Dented or creased tubes | Short bunks, bunks under a strake or weld seam, point contact on narrow bunks | Long, wide bunks or saddles; align under the tube body |
| Boat lands crooked | Wind or current while loading; no guide posts | Add guide posts; load into the wind; see boat sits crooked on lift |
| Deck brackets cracking near stern | Center tube unsupported on a tritoon | Add center bunk or stern support |
| Lift racked or tipped in storm | Wind on raised boat with top up | Lower tops, use tie-down kits, lower boat height |
| Engine skeg hits lift or bottom | Engine not trimmed up, shallow water | Trim up before loading; check depth |
| Pitting on aluminum tubes | Dissimilar metals or stray current in saltwater or brackish water | Isolate contact points; have dock wiring checked |
What most guides get wrong
Many guides treat a pontoon as just "a light boat with a big footprint." The weight distribution is the real story. Brochure weights for pontoons are often hull-only, and a modern tritoon with a large outboard can weigh 40 to 60% more than its hull figure once loaded. That weight is concentrated at the stern and, on tritoons, on the center tube. Sizing to brochure weight and supporting only the outer tubes is the most common route to dented tubes, cracked brackets and an overworked lift.
Safety: Never stand or swim under a raised pontoon; the deck hides how close the tubes are to your head. Powered lifts need a GFCI or ELCI protected supply installed by a licensed electrician, and family swimming areas near docks are exactly where electric shock drowning risk from faulty wiring matters most.
Costs in 2026
For most pontoons, expect free-standing lake lifts in the 3,000 to 12,000 USD installed range in 2026, with pontoon bunk kits, solar power, remote control and canopies pushing toward the top. Larger tritoons on piling-mounted vertical lifts in the 10,000 lb class typically fall in the 9,000 to 18,000 USD range, before any new pilings. Floating lifts run roughly 6,000 to 30,000+ USD. These are typical ranges that vary by region, water conditions and installer, not quotes. See the cost index.
Frequently asked questions
What size lift do I need for a pontoon boat?
Add the pontoon's hull weight, engine, fuel at 6.1 lb per gallon, batteries and gear, then add 15 to 25% margin. Many 20 to 22 ft two-tube pontoons land around 3,500 to 4,500 lb with margin, while 24 ft and larger tritoons with big outboards often need 5,500 to 7,000 lb lifts. Always check whether the brochure weight includes the engine.
Do tritoons need a special boat lift?
Tritoons need a lift wide enough for the boat and bunks positioned for three tubes. Many benefit from a center bunk or stern support, because much of the engine and fuel weight sits over the center tube. Lift makers offer tritoon-specific bunk kits; check that your lift model supports one and that its capacity covers the loaded tritoon weight.
Can I use a V-hull boat lift for a pontoon?
Usually only after changing the bunks. The lift frame may be suitable if its capacity and width fit, but V-hull bunks are angled and spaced for a keel and chines. A pontoon needs long bunks or saddles placed under each tube. Most manufacturers sell conversion kits so the same lift frame can carry a pontoon.
How long should pontoon lift bunks be?
Long enough to support most of the tube length, with many kits running bunks roughly 14 to 20 ft or more depending on boat length. Short bunks concentrate load near the cradle beams and can dent tubes. The boat builder or lift manufacturer can confirm minimum supported length and whether any overhang limits apply at the bow or stern.
Should I leave the bimini up on a pontoon lift?
Fold it down whenever the boat sits on the lift unattended in windy weather. A raised pontoon with the top up has a large sail area, and wind pushes on the lift frame and the top itself. Free-standing lifts are especially sensitive. Folding the top, removing enclosures and using a tie-down kit all reduce the risk of racking or tipping.
Sources and further reading
- U.S. Coast Guard Boating Safety resources, uscgboating.org
- ABYC E-11, AC and DC Electrical Systems on Boats, and related corrosion guidance, abycinc.org
- NFPA 70, National Electrical Code, Article 555, nfpa.org
- Aluminum Association alloy designations (marine aluminum used in tubes and lift structures)
- State DNR shoreline and seasonal structure rules (requirements vary by state)
- Pontoon builder owner's manuals (weights, lifting and support guidance) and lift manufacturer pontoon kit instructions