Wrestling with a heavy dinghy and outboard motor at the swim platform is a common frustration for many boaters. What should be a moment of excitement, arriving at a beautiful anchorage, can quickly turn into a stressful chore.
Choosing the right marine davit system transforms this task into a safe, simple, one-person job. This guide walks you through the critical factors for selecting the perfect system: calculating your total tender weight and matching a system to your unique boating style.
How to Calculate Your Total Tender Weight
The single most important factor in choosing a dinghy davit is the total weight of your tender package when fully loaded. Underestimating weight is the most common mistake boaters make, often leading to mechanical strain or safety issues.
To find your total lifting weight, use this formula:
- Dinghy Hull Weight: Use the manufacturer’s listed “dry weight” for your inflatable or RIB.
- Outboard Motor Weight: Account for the engine, especially heavier modern 4-stroke outboards.
- Fuel & Essential Gear: Include a full fuel tank (approx. 6.1 lbs per gallon), battery, anchor, oars, and safety gear.
Pro Tip: Always round your final number up by 10%. This “safety buffer” ensures your davit operates within its optimal stress range rather than at its absolute limit.
Selecting Your Performance Tier Based on Capacity
Once you have calculated your total tender weight, your choice is dictated by the specific lifting requirements of your vessel. We categorize our systems into two distinct performance tiers to ensure you have the correct mechanical advantage for your load.
The 450 lb (204 kg) Threshold: Efficient Manual Retrieval
For owners of lighter RIBs and inflatables, the priority is often reliability in remote locations. When your total weight falls under 450 lbs, a system utilizing mechanical gear reduction is the industry standard.
- Engineering Advantage: Our Manual Gear-Reduction system features a precision 25:1 worm gear ratio. This specific engineering allows a single crew member to generate a significant lifting force without the need for onboard electrical integration.
- Safety Priority: In manual systems, a self-braking mechanism is essential. It ensures the tender remains locked in position even if the operator releases the handle, preventing accidental “kick-back” on the swim platform.
The 800 lb (363 kg) High-Capacity Tier: Powered Ease
As tender packages become more complex—incorporating center consoles and heavy 4-stroke outboards, the physical demand of retrieval increases. For loads up to 800 lbs, an integrated 12V DC system is recommended to manage the increased stresses on the hull mounting points.
- Operational Efficiency: The transition to electric operation is less about “luxury” and more about single-handed vessel management. Being able to retrieve a heavy tender via push-button allows the captain to remain focused on the boat’s position in high-wind or high-current scenarios.
- System Redundancy: High-capacity systems should always include an emergency deployment override. This ensures that even in a “dark boat” (total power loss) scenario, your tender remains accessible for safety.
Quick-Reference Sizing Matrix
Use this matrix to identify which engineering tier aligns with your calculated tender weight.
| If Your Total Weight Is… | Recommended System Type | Key Benefit |
| Under 450 lbs (204 kg) | Manual Gear-Reduction | Power-free reliability & simplicity |
| 450 lbs – 800 lbs (363 kg) | Electric 12V DC | Effortless retrieval for heavy tenders |
| Construction Material | 316L Marine Stainless | Maximum corrosion resistance |
| Installation | Custom Hull Brackets | Structural integrity & factory fit |
Considering Your Boating Style: Reliability vs. Convenience
Beyond the numbers, consider your cruising habits. The Manual System offers “absolute reliability,” working every time regardless of your boat’s electrical state—a favorite for long-range cruisers. In contrast, the Electric System offers “ultimate convenience” for those who frequently move anchorages. You can see examples of both systems in action in our project gallery.
Custom Fit: Why Hull Design Matters
A generic, one-size-fits-all davit rarely provides the security needed for offshore conditions. A proper fit is crucial for the structural integrity of your swim platform.
Since 1987, SeaWise Marine has specialized in custom mounting brackets to ensure a factory-finished look. Our design team has engineered solutions for the industry’s most popular boat brands, including:
- SeaRay & Meridian
- Ranger Tugs & Nordic Tugs
- Grand Banks & Classic Yachts
Conclusion: Investing in Safety and Simplicit
Choosing a davit system is an investment in your safety. By selecting a system built from electro-polished 316L Marine-Grade Stainless Steel and backed by an industry-leading 5-Year Warranty, you are ensuring years of trouble-free operation.
Stop wrestling with your outboard and start enjoying the destination.
Ready to upgrade your vessel?
Our experts are available 7 days a week to help you size your system.
- Phone: (604) 946-0551
- Email: derek@seawisemarine.com
