Know Your Lifting and Blocking Points: A Critical Haul-Out Safety Guide

Haul-out day is stressful enough without wondering whether your boat is being lifted and blocked correctly. But here’s the thing most boat owners don’t realize: improper lifting or blocking can cause serious, expensive damage to your hull—damage that might not even be visible until much later.

We learned this lesson the hard way in Thailand.

When Things Go Wrong: Our Thailand Experience

Amy and I had hauled Starry Horizons out many times during our circumnavigation. We’d developed a routine: arrive early, watch the process carefully, and trust that experienced yard crews knew what they were doing.

At a boatyard in Thailand, the crew assured us they’d hauled out plenty of catamarans before. They knew where the bulkheads were and how to support the hulls properly. The haul-out itself went fine—the hydraulic trailer lifted us smoothly out of the water.

The problem came when they positioned the jack stands.

Normally, Starry Horizons would have had additional support under the mini keels—that’s how she sat at the factory on delivery day. But we needed to do work on the mini keels themselves, so the full weight of the boat had to be supported entirely on the bulkheads. We explained this to the yard crew, and they confirmed they understood.

Despite their confidence and experience, one of the critical blocking points was missed. They thought they had a stand positioned over a bulkhead, but it was actually off by several inches. We didn’t catch it immediately because the boat appeared stable and level. It wasn’t until several days later, during our inspection, that we discovered a crack in the hull near where a stand should have been placed but wasn’t.

It was a perfect storm: no support under the mini keels and a stand that was slightly misplaced. The misplaced stand was on an unsupported section of hull which then flexed under the boat’s weight, causing gelcoat cracking that extended into the laminate. What should have been a routine haul-out turned into an unexpected repair project—and an painful lesson.

That’s when we learned: “We know where the bulkheads are” isn’t good enough—especially when the support configuration is different from normal.

After Thailand, we changed our approach entirely. We obtained the manufacturer’s lifting and blocking diagrams, and from that point forward, we provided them to every yard before haul-out day. No exceptions. Even experienced crews can make mistakes, and having the exact specifications eliminates guesswork—particularly when you have non-standard requirements like work that prevents using normal support points.

Why Lifting and Blocking Points Matter

Your boat’s hull was engineered to be supported at specific points that distribute weight across structural members—bulkheads, stringers, and reinforced sections of the hull. Random placement of lift straps or jack stands can put stress on unsupported areas, leading to:

From improper lifting:

• Hull deformation during the lift
• Gelcoat stress cracks
• Structural damage to stringers or bulkheads
• Potential catastrophic failure if straps slip

From improper blocking:

• Hull deformation from concentrated weight
• Gelcoat cracking that extends into laminate
• Instability while on the hard
• Long-term structural issues from prolonged improper support

The forces involved are significant. A 40-foot cruising boat can weigh 20,000-30,000 pounds or more. When that weight isn’t properly distributed, even a strong hull can suffer damage.

Understanding Manufacturer Specifications

Most boat manufacturers provide detailed diagrams showing:

1. Lifting points - Where travel lift straps should be positioned
2. Blocking points - Where jack stands should support the hull

Some may even offer:

3. Load distribution requirements - How weight should be spread
4. Special considerations - Any hull-specific requirements

These aren’t suggestions—they’re engineering specifications based on your boat’s construction and design.

Where to Find Your Diagrams

• Owner’s manual - Usually in the technical specifications section
• Manufacturer’s website - Often in owner resources or downloads
• Boat manufacturer directly - Contact customer service if you can’t locate them
• Boat builders’ forums - Other owners may have shared copies
• Previous owner - If you bought used, ask if they have documentation

If your boat is older or from a manufacturer no longer in business, you may need to work with a marine surveyor to determine proper lifting and blocking points based on hull construction.

The Haul-Out Process: What to Verify

Before the Lift

1. Provide documentation Give the yard your manufacturer’s lifting and blocking diagrams well before haul-out day. Don’t assume they have this information, even for common boat models.

2. Walk through the plan Review the lift plan with the yard crew. Point out the specific locations where straps and stands should go.

3. Ask about experience If your boat is unusual (catamaran, trimaran, light displacement, custom build), verify the yard has experience with similar vessels.

During the Lift

1. Verify lifting point positioning Before the boat comes out of the water, physically check that lifting points are positioned correctly—whether that’s travel lift straps, hydraulic trailer pads, or crane slings.

2. Watch the lift Stay present during the entire process. Look for:

• Even lifting (boat staying level)
• No unusual hull flexing
• Lifting apparatus staying in position
• Any concerning sounds or movements

3. Communicate If something doesn’t look right, speak up immediately. It’s much easier to adjust before the boat is fully out of the water.

After the Lift (Before Blocking)

1. Verify stand positions Before the boat settles onto stands, confirm each stand is positioned at a specified blocking point.

2. Check for proper pad contact Stands should make contact with the hull across their full surface area—no point loads.

3. Verify stability The boat should sit level and stable on all stands.

Special Considerations for Different Hull Types

Catamarans and Multihulls

Catamarans require careful attention to both hull loading and the connection between hulls. Improper support can:

• Stress the bridge deck connection
• Cause differential settling between hulls
• Create torsional loads on the structure

Many yards have less experience with multihulls, making it even more critical to provide detailed specifications and verify everything carefully.

Light Displacement Boats

Modern light-displacement cruisers may have thinner laminates and require more careful support distribution. Point loads that might be fine on a heavy displacement boat can cause damage to lighter construction.

Custom or Unusual Designs

If you can’t find manufacturer specifications, consider hiring a marine surveyor to determine proper lift and blocking points based on structural analysis.

Creating Your Haul-Out Documentation

Our Thailand experience taught us that even experienced yards can make mistakes. That’s when we started keeping comprehensive haul-out documentation:

• Lifting diagram - Clear photos or drawings showing exact strap positions
• Blocking diagram - Precise locations for all jack stands
• Special instructions - Any boat-specific requirements
• Photos from successful haul-outs - Visual reference of correct positioning

We obtained these from our boat manufacturer after the Thailand incident and stored everything in MaintenanceROS so it was accessible from anywhere—including when we’re at a boatyard in a foreign country.

Red Flags to Watch For

Trust your instincts. If something doesn’t look or feel right, stop the process and reassess. Specific red flags include:

• Yard crew dismissing your diagrams (“We do it this way for all boats”)
• Visible hull flexing during the lift
• Stands positioned on flat sections without structural support underneath
• Boat settling unevenly on stands
• Resistance to your questions or involvement

A good yard will welcome your documentation and appreciate an owner who cares about proper procedures.

How MaintenanceROS Helps Prevent Haul-Out Problems

After our Thailand experience, we realized that proper haul-out preparation requires organization and accessible documentation—exactly what MaintenanceROS was designed to provide.

Create a Haul-Out Preparation Checklist

MaintenanceROS includes a customizable checklist library with a pre-made haul-out preparation checklist that you can adapt to your specific boat and needs:

You can customize this checklist based on your boat’s specific requirements, past experiences, or lessons learned. Each time you schedule a haul-out, the checklist ensures you don’t forget any critical preparation steps.

Attach Critical Documentation

Here’s where MaintenanceROS becomes particularly valuable: you can attach your manufacturer’s lifting and blocking diagrams directly to your haul-out checklist.

This means:

• Your critical documentation travels with your checklist
• You can access diagrams from your phone or tablet at the boatyard
• No more searching through paper files or digging through email
• Everything you need is in one organized location

You can also attach:

• Photos from previous successful haul-outs showing correct positioning
• Any special requirements or notes specific to your boat
• Documentation of non-standard configurations (like our mini keel situation)

When you’re standing at a boatyard in a foreign country trying to explain your boat’s specific requirements—potentially through a language barrier—having instant access to visual diagrams on your phone is invaluable.

The Bottom Line

Our Thailand experience taught us that even experienced yards can make mistakes—especially when there are non-standard requirements. Proper preparation, clear documentation, and systematic verification are your best defense against costly damage.

You are your boat’s best advocate. Having your lifting and blocking diagrams accessible, paired with a preparation checklist that ensures you don’t skip critical verification steps, could save you thousands in repairs and weeks of stress.

After our experience, we never skipped these steps. And neither should you.

Want to keep all your critical boat documentation—including lifting and blocking diagrams—organized and accessible anywhere? Try MaintenanceROS free for 30 days and always have the information you need at your fingertips.