Boat Lift Sizing in Florida: Capacity, Wet Weight and Lift Types

ShoreMaster's rule is dry weight plus fuel plus gear: take the manufacturer's dry weight, add the fuel tank capacity in gallons times 6 pounds, add about 500 pounds for gear, batteries, coolers and people, then add a 20 percent safety margin. If that lands between two lift sizes, size up. A lift is rated for its capacity and not a pound more, and capacity cannot be upgraded later. [shoremaster.com]

Hurricane Boat Lifts frames it as total load equals dry weight plus fuel plus gear plus water plus a safety margin, with gasoline at about 6 pounds per gallon. The water term covers livewells, bilge water and rain, and the company recommends the higher end of a 10 to 20 percent margin in salt water. [hurricaneboatlifts.com]

Worked example, with made-up figures. A boat listed at 4,000 pounds dry with a 100-gallon tank: 4,000 plus 600 for fuel plus 500 for gear is 5,100 pounds. Add 20 percent and you are at 6,120, so the lift you want is the next rated size above that, not the one rated at 6,000.

So what size boat lift does a 24-foot boat need? Length is the wrong input. Two 24-footers can differ by thousands of pounds depending on hull, power and fuel, which is why every manufacturer sizes by weight. Find the dry weight on the builder's spec sheet, then run the formula.

A cradle lift, usually a 4-post lift, stands on its own four pilings with the cradle hanging between them. It is the most common residential lift in Florida and carries the widest range of capacities. An elevator lift mounts to pilings along the seawall or dock face and lifts the boat on an angled track, which keeps it out of the channel and suits narrow canals. PWC lifts are typically rated in the 1,500 to 2,500 pound class. [mcidocks.com]

Floating lifts sit in the water with no pilings of their own and are sometimes used where pilings cannot be driven or where the owner wants something they can move. They trade the fixed lift's stability and capacity for that flexibility; ask the manufacturer for the rating and the mooring requirements before assuming one fits a canal with boat traffic.

Is a boat lift worth it in salt water? The lift's job is to keep the hull, running gear and through-hulls out of the water between trips, which cuts growth, corrosion and the bottom work that comes with them. Whether it pays back depends on how much you use the boat and what a haul-out costs you in time; most owners in our four counties decide yes.

Florida's sovereign-lands rule caps a dock at 25 percent of the width of the waterbody, and a lift's pilings and cradle have to sit inside that limit. [law.cornell.edu]

State law also gives lifts their own exemption size: up to 500 square feet, or 200 square feet in Outstanding Florida Waters. [flsenate.gov]

On a canal where a cradle lift would leave too little channel, an elevator lift along the seawall or a lift set parallel to the wall keeps the boat out of the traffic lane. Cities set their own projection caps under the state 25 percent; check the dock-construction page for your city under our locations before you pick a lift, because the canal width and the city rule decide the type before the boat does.

Tide range also sets the lift's beam height and stop positions. Too little travel and the boat sits in the water at a king tide; too much and you are climbing into it at low water.

Salt water attacks a lift cable from inside the lay, between the strands, where the damage is hardest to see from the dock. That is why cable replacement is a matter of condition rather than a date on the calendar: we do not publish a service life in years, because it depends on the cable, the load it carries and how often the lift runs.

The federal wire rope rule for construction cranes is a useful model for how to judge a cable, even though it does not cover a private boat lift. It calls for a visual check before each use, a monthly inspection, and an inspection by a qualified person at least every 12 months, and it treats significant corrosion of the rope, or significantly corroded end connections, as grounds for taking the rope out of service. [osha.gov]

Rinse cables, drums and the motor housing with fresh water after salty trips, keep the cables spooling evenly on the drum, and have the gearbox and motor serviced on the manufacturer's schedule. Frayed strands, rust bleeding from the cable, and a cradle that comes up unevenly are all reasons to stop using the lift until it is checked. On a four-post lift the boat hangs on four cables, so when one lets go the load shifts onto the other three, which is how a cable problem becomes a boat problem.

Lift motors and the dock's receptacles fall under the same electrical rules as the rest of the dock: ground-fault protection and a qualified electrician's inspection, because electric shock drowning is a real dock hazard. [nfpa.org]

A lift is a good place for a boat in a squall and a bad place in a hurricane. Surge lifts hulls off cradles, and wind works a boat against its bunks for hours. Follow your lift manufacturer's written storm guidance and your insurer's requirements, which usually mean moving the boat to a haul-out or a protected mooring when a storm is forecast.

Storm surge can uplift pilings, including the ones under a lift, and a lift piling that has moved changes the geometry the cables and beams rely on. Inspect the pilings before you put the boat back on the lift after a storm. [dockdogsfl.com]

Before the storm: cut power to the lift at the panel, secure or remove the canopy, and photograph the lift and pilings. The full checklist is in our guide to dock repair after a hurricane.