Boat Lift Guide Posts and V-Sides: Getting the Boat Onto the Cradle in the Same Spot Every Time
Quick answer
Guide posts are vertical padded posts on the cradle that funnel the boat into position; V-sides are angled side bunks, common on PWC and cantilever lifts, that center the hull as it lifts. Set guide posts about 2 to 4 inches per side wider than the hull where they touch, tall enough to show at least 2 to 3 feet above the highest expected water, and pair them with a bow stop so the boat lands in the same fore and aft spot every time.
On this page
A boat lift only works as well as the boat's position on it. Drive on a few inches off center and one bunk carries more than its share; stop a foot too far forward and the front cables carry the engine's weight as well as the bow's. Guide posts, V-sides, and bow stops exist to make the right position the easy one, especially in crosswind, current, or with an inexperienced driver at the helm.
What each part does
| Part | What it is | Main job | Where common |
|---|---|---|---|
| Guide posts | Vertical posts (often aluminum or steel with PVC or vinyl sleeves) mounted on the cradle beam ends | Show the cradle position above water; keep the boat between the bunks laterally | Vertical, elevator, cantilever lifts |
| Guide-ons with rollers | Guide posts with vertical rollers instead of sleeves | Let the hull roll along the post rather than rub | Lifts in current or wind |
| Side guide bunks | Short carpeted bunks set vertically or steeply angled at the cradle sides | Wider contact area than a post for heavy or wide hulls | Larger vertical lifts |
| V-sides | Angled side bunks forming a V that the hull nests into | Center the hull as the cradle rises; support the sides | PWC lifts, some cantilever lake lifts |
| Bow stop | Padded stop or V-block at the front of the cradle | Set fore and aft position repeatably | Most lift types |
For other add-ons like catwalks, lights, and auto stops, see boat lift accessories.
Setting guide post spacing
Guide posts should guide, not grip. The boat should be able to enter without scraping in calm water, and should be stopped from drifting off the bunks in a crosswind.
Where to measure the boat
Posts do not touch the boat at its maximum beam unless they are tall enough to reach the rub rail. Most posts contact the hull below the rail, near the chine or on the topsides above the waterline, where the hull is narrower. Measure the boat's width at the height the posts will actually contact, at the fore and aft positions of the posts, not the brochure beam figure.
The spacing rule
Set the inside distance between opposing posts to the hull width at the contact height plus about 2 to 4 in per side (4 to 8 in total). Closer than 2 in per side and the boat scrapes on entry, especially if it yaws slightly. Wider than about 6 in per side and the posts stop doing their job, since the boat can sit noticeably off center on the bunks before touching them.
Worked example: post spacing for a 102 in beam deck boat
A deck boat has a brochure beam of 102 in (8 ft 6 in). Measured at 18 in above the waterline, where the posts will contact the topsides, the hull is 96 in wide at the aft posts and 90 in wide at the forward posts (the hull narrows toward the bow).
- Aft posts: 96 + 2 x 3 = 102 in inside spacing (3 in per side clearance).
- Forward posts: 90 + 2 x 3 = 96 in inside spacing.
- Checking the lift: if the cradle beams allow posts at a maximum inside spacing of 108 in, both settings fit.
Setting the forward posts narrower than the aft posts creates a gentle funnel that centers the bow as the boat moves forward. If the lift's post brackets only allow a single spacing, set to the aft width and rely on the bow stop to center the bow. More on slip widths and clearances is in dock and slip layout.
Setting guide post height
Posts should be visible above water when the cradle is fully lowered at the highest water level of the year, so the driver can see the target. A common target is at least 2 to 3 ft of post above the water at that highest level. At the other extreme, the posts must not hit the boat's rub rail, gunwale, or anything overhanging the hull when the cradle is fully raised.
Worked example: post height on a lake with a 3 ft seasonal swing
A lake rises 3 ft between late summer low water and spring high water. At high water, the fully lowered cradle beam sits 4 ft below the surface (enough to float the boat off with margin). The boat's rub rail sits 3.5 ft above its keel, and the bunks put the keel about 8 in above the beam.
- To show 2.5 ft above the surface at high water, the post must reach 4 + 2.5 = 6.5 ft above the cradle beam.
- The rub rail sits about 0.67 + 3.5 = 4.2 ft above the beam when the boat is on the cradle.
- A 6.5 ft post would extend 2.3 ft above the rub rail. That is acceptable only if the post is outboard of the rail and clear of any flared bow or overhanging platform. If the rail overhangs the post line, shorten the post, use a post set outboard of the rail line, or use a tilting or removable post top.
Water level swings and the cradle depth they require are covered in water depth requirements and the water depth calculator. In tidal water, calculate for the highest normal tide you will load on.
Field tip: Wrap a band of reflective tape near the top of each post. At dusk, a flashlight or the boat's navigation lights pick up the posts long before the cradle is visible.
V-sides on PWC and cantilever lifts
A V-side cradle supports the hull on angled side bunks rather than on two flat bunks underneath. PWC lifts use them because jet ski hulls are deep, narrow, and have intake grates and ride plates on the bottom that should not carry the craft's weight. As the cradle rises, the angled sides push the hull toward the center, so a ski that came in slightly off line ends up centered.
Setting V-side angle and width
- The V-side angle should match the hull side angle at the contact area, the same principle as matching bunk angle to deadrise (see adjusting bunks for your hull).
- The hull should bear on the V-sides along the smooth hull sides, below the sponsons and above the chine, not on the sponsons, a strake, or the intake grate.
- Width should let the hull settle with the keel clear of any cross member. If the keel touches first, the V-sides are set too wide.
- Many PWC cradles are model specific. After changing skis, recheck the fit; a cradle sized for an older, narrower ski may support a newer, wider hull only on its upper edges.
See PWC lifts for lift types and PWC lift vs drive-on port for floating alternatives.
Bow stops
A bow stop sets fore and aft position. Without one, drivers tend to stop short, leaving the boat's center of gravity aft of the lift's midpoint and overloading the rear cables. Set the bow stop so that when the bow touches it, the boat's center of gravity is near the middle of the cradle and the bunks reach to within about 6 to 12 in of the transom. A padded V-block that catches the stem also helps center the bow. Many manufacturers rate lift capacity with the load centered, so this is a capacity issue as well as a convenience.
Driving on in wind and current
- Approach into the strongest force (wind or current) where the slip orientation allows. A boat holds a line far better when stemming the current than when being set sideways by it.
- Use the upwind or up-current posts as the reference, aiming to keep that side just clear. The boat will be pushed toward the downwind posts.
- Enter slowly, in gear, with steerage. Idle forward with short bursts; too slow in current and you lose steering, too fast and you hit the bow stop hard.
- Roller guide-ons are worth the extra cost where crosswind or current is the norm, since the hull rolls along them instead of rubbing.
Safety: Never stand, swim, or reach under a raised boat or cradle while adjusting posts or V-sides. Adjust with the boat off the lift and the cradle on its stops or blocked, and turn lift power off at the breaker. Do not enter the water near a powered lift; dock circuits must be GFCI or ELCI protected, and electric shock drowning can occur with no visible warning. Leave wiring for lift lights or switches to a licensed electrician (see boat lift electrical).
Failure modes and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Hull scuffs on entry | Posts too close, sleeve worn, or no rollers in current | Widen to 2 to 4 in per side; replace sleeves; add rollers |
| Boat sits off center on bunks | Posts too wide or bent | Narrow spacing; straighten or replace posts. See boat sits crooked on lift |
| Posts bent outward | Hard landings or boat pushed against them in wind | Replace; consider heavier posts or side guide bunks |
| Posts hit rub rail when raised | Posts too tall or too far inboard | Shorten, move outboard, or use removable tops |
| PWC rides up one V-side | V-sides at wrong angle or width; ski entered off line | Re-angle to match hull; add a bow stop |
| Boat stops short every time | No bow stop or stop set too far aft | Set bow stop for centered CG |
| Cracked or missing PVC sleeves | UV aging, impact, ice | Replace sleeves; check posts for corrosion underneath |
Cost and installation
Guide post kits for residential lifts commonly run about $200 to $800 per pair in 2026, with roller guide-ons, side guide bunks, and stainless or heavy-duty versions higher. Bow stops typically cost $75 to $300. Installation is usually a bolt-on job to the cradle beam ends with the boat off the lift. These are typical ranges that vary by brand, region, and installer, not quotes. Check that any aftermarket post is compatible with your cradle beam profile; see finding boat lift parts.
Regional differences
- Tidal saltwater: posts need to be tall enough for loading at high tide, and the lower ends spend time submerged, so use corrosion-resistant posts and check for galvanic corrosion at the bracket. See tidal and saltwater installations.
- Rivers: current makes roller guide-ons and narrower forward posts more valuable.
- Ice country: remove posts or raise the cradle before freeze-up; ice movement bends posts.
- Hurricane country: remove tall posts and boat before a storm as part of hurricane preparation; posts act as levers when debris or surge pushes on them.
Frequently asked questions
How far apart should guide posts be on a boat lift?
Set the inside spacing to the hull's width at the height where the posts touch, plus about 2 to 4 inches per side. Measure the actual hull at that height, not the brochure beam, because hulls are narrower below the rub rail and toward the bow. Setting the forward posts slightly narrower than the aft posts helps funnel the bow to center.
How tall should boat lift guide posts be?
Tall enough to show at least 2 to 3 feet above the water when the cradle is fully lowered at the highest water level you load in, so the driver can see them. They must also clear the rub rail, gunwale, and any flared bow when the boat is raised. In lakes with big seasonal swings or tidal water, calculate for the highest level.
Do I need guide posts on my boat lift?
They are optional but strongly recommended where wind or current pushes the boat sideways, where the cradle is hard to see underwater, or when different people drive the boat on. Posts make centering repeatable, which keeps bunk and cable loads balanced. In a sheltered slip with an experienced driver, a bow stop alone sometimes suffices.
What are V-sides on a PWC lift?
V-sides are angled side bunks that form a V for the jet ski hull to nest into. As the cradle rises, they push the hull toward center and carry its weight on the smooth hull sides, keeping load off the intake grate and ride plate. They should match the hull's side angle, so recheck the fit when you change to a different ski model.
Should guide posts have rollers?
Rollers help where crosswind or current regularly pushes the boat against the posts, since the hull rolls along instead of rubbing on a sleeve. In calm, sheltered slips, padded PVC or vinyl sleeves work well and cost less. Either way, replace cracked sleeves or seized rollers promptly, because a damaged guide scuffs the hull every time you load.
Sources and further reading
- Boat lift manufacturer owner's manuals and accessory installation instructions (guide post brackets, bow stops, PWC cradles)
- NOAA Tides and Currents, tide predictions and water level data, tidesandcurrents.noaa.gov
- U.S. Coast Guard boating safety resources, uscgboating.org
- NFPA 70, National Electrical Code, Article 555, nfpa.org
- ABYC standards, abycinc.org