Cradle & bunk geometry
A same-capacity lift with wrong bunks or cradle geometry is not a fit. Aft-weight-heavy outboards need geometry-matched cradles.
Ownership Intelligence
Boat Lift & Dock Planning Guide — how to size a boat lift for any boat.
Quick Answer
Total the boat's dry (or lightship) weight + full fuel + full water + gear, add ~20% safety margin, and match to a lift capacity — then verify the cradle, pilings, dock and depth professionally.
LAST UPDATED July 27, 2026
The Method
Wet weight × 1.20 — the planning floor
A simple, defensible calculation that produces a starting range for discussion. It is not a lift-engineering approval.
Planning floor = (Published weight + Fuel × 7.5 + Water × 8 + Gen fuel × 7.5) × 1.20
Use the manufacturer's exact weight term — dry weight, lightship displacement, or light craft mass. Do not translate one term to another; each is defined differently.
Preliminary planning only. Final lift capacity, cradle geometry, pilings, dock structure, water depth and vessel configuration require professional verification.
Lift Capacity Classes
Common residential lift classes
Starting ranges only. Every real decision requires a Dock-to-Deck review that accounts for cradle, pilings, depth and configuration.
| Capacity class | Typical planning range |
|---|---|
| 10,000 lb | Center consoles ≤ ~24 ft; light bay boats. |
| 15,000 lb | Smaller premium center consoles / dayboats up to ~28 ft. |
| 20,000 lb | Mid-size center consoles, dayboats, walkarounds in the ~30-33 ft range. |
| 25,000 lb | Premium 33-36 ft dayboats and heavy center consoles; often with limited allowance. |
| 30,000 lb | 38 ft class dayboats and premium center consoles fully loaded. |
| 35,000-40,000 lb | Larger platforms with generator, twin/triple outboards, generator, gear; frequently custom cradle. |
| 50,000 lb+ / custom / wet slip | Flagship day-yachts and offshore center consoles; wet slip often the right answer. |
What Actually Decides Fit
Weight is one input — six others matter as much
Piling placement & structure
Piling spacing, dock structure, cross-bracing and neighboring dock features constrain lift width and travel.
Controlling depth at low tide
The lowest tide governs — not the average. Canal-mouth shoaling can eliminate an otherwise-workable dock.
Beam with hardware
Real beam includes rub rails, fenders and hardware. Balconies and swim platforms further change the operating envelope.
Fuel + water + gear + generator
Every 100 gallons of fuel is about 750 lb; every 100 gallons of water is about 800 lb. Add batteries, tackle, provisions.
Air draft (hardtop, radar, tower)
Bridge clearance is measured to the highest fixed point — hardtop, radar arch, outriggers, tower and antennas.
Apply the Method
Brand-specific ownership pages
The same method, applied to the three brands we cover in depth.
FAQs
Boat lift & dock planning — common questions
How do I size a boat lift?
Total the boat's dry (or lightship) weight + full fuel + full water + gear, add ~20% safety margin, and match to a lift capacity — then verify the cradle, pilings, dock and depth professionally.
What is the safety margin for a boat lift?
Industry standard is roughly 1.20× the estimated loaded weight. This absorbs future gear, aging cables, and off-center loading — it is not a substitute for professional lift-engineering review.
How much does fuel weigh?
Gasoline and diesel both weigh roughly 7.5 lb per gallon for planning purposes. A 300-gallon fuel load adds about 2,250 lb.
How much does water weigh?
Fresh water is 8.34 lb per gallon; we round to 8 for planning. A 50-gallon fresh-water tank adds about 400 lb.
Does published dry weight equal lift-design weight?
No. Dry weight (or lightship/displacement/light-craft-mass depending on the manufacturer) is the baseline. Real lift capacity must account for fuel, water, batteries, gear, options, cradle geometry, and safety margin.
Is a lift always the right answer?
No. Larger platforms, deep-draft boats, or docks with piling/depth constraints often work better in a wet slip. The right choice depends on property, boat, use frequency and budget.
Verify Your Setup
The method above is a starting range. Your dock, lift and route need professional verification.
Reviewed by Michael Johnson · YSL12498