The tender garage is the most expensive box on the boat to get wrong. Once it is built, it is built. Stretching it 200 mm later means cutting structure; lifting the deckhead 100 mm means moving the deck above. Owners and yards get garage sizing right by working backwards from the tender envelope, not forwards from the GA. This guide walks through the process the way a build manager actually runs it: hard constraints first, then envelope, then door, then davit, then the soft factors that decide which boat finally goes in.
The short answer first, because it is the question everyone arrives with. As an indicative envelope: a 50 m yacht carries roughly a 7.0 to 7.5 m garage tender, a 60 m yacht 8.0 to 8.5 m, a 70 m yacht 9.0 to 9.5 m and an 80 m yacht 10 to 11 m, with internal heights commonly only 1.4 to 1.7 m and tolerances measured in millimetres. Height, not length, is the constraint that most often kills a tender choice. The rest of this guide is how to derive a real box from a real boat rather than read it off a chart.
For background on the tender categories that drive the envelope, start at the tenders pillar and the tender garage sizing spoke; this guide is the practical extended version with the numbers attached.
Why this matters more than it used to
Three things have made the garage harder to size in the last decade:
- Tenders are bigger. A 10.5 m limousine that would have been an outlier in 2014 is the standard 70 m yacht spec today. Owners want hospitality on the run, not just transport.
- Hardtops are everywhere. Climate-controlled cockpits, retractable T-tops, and tall windscreens add height that early-2010s garages did not anticipate.
- Hybrid powertrains add mass and footprint. Battery banks live under the cockpit sole and bring 200 to 400 kg of unsprung weight that the davit and cradle have to swallow.
The result is that 50 to 60 m yachts built in the last build cycle are routinely caught with garages too small for the tenders the owner now wants. Refit is the lever, but it is a 12 to 18 month conversation. Build managers get this question right at concept stage by reserving more envelope than the current tender needs.
The seven dimensions that actually matter
Walk into a yard's GA review and these are the numbers you should be looking at:
| Dimension | What it constrains | Typical clearance to design for |
|---|---|---|
| Garage internal length | LOA of tender on cradle | 100 mm bow, 150 mm stern (for engines) |
| Garage internal width at deck | Maximum beam at the rubrail | 75 mm each side |
| Garage internal width at sole | Cradle footprint and walking clearance | 100 mm each side |
| Garage internal height | T-top, screen, mast, antenna | 100 mm vertical |
| Door clear opening width | Tender crossing the threshold | 50 mm each side, dynamic |
| Door clear opening height | Tender exiting on cradle or floating | 75 mm above tallest fixed point |
| Door sill height above DWL | Float-out depth and ramp angle | Set by launch system, not by hull |
The most common failure mode is height, not length. Garages get specced to a tender length that fits, then a year later the tower or hardtop hits the deckhead during launch. Always engineer 100 mm of vertical clearance over the tallest fixed point of the tender at full launch attitude.
The Williams Jet Tenders journal covers similar ground from the production builder's perspective and is a useful sanity check against any yard's number.
Garage architectures: which one fits your yacht
Garage sizing depends on the launch architecture. Each has different envelope rules.
Flush aft garage with stern door
The classic arrangement on 50 to 80 m flybridge motoryachts. A horizontal door drops from the transom, the tender rolls aft on a cradle and floats off. The constraint is door height above DWL: too low and the boat lifts on the cradle as it floats, too high and the cradle has to extend under water.
Typical envelope on this arrangement:
- 50 m yacht: 7.0 to 7.5 m tender, 2.5 m beam, 1.4 m height clearance.
- 60 m yacht: 8.0 to 8.5 m tender, 2.7 m beam, 1.5 m height.
- 70 m yacht: 9.0 to 9.5 m tender, 2.9 m beam, 1.6 m height.
- 80 m yacht: 10.0 to 11.0 m tender, 3.1 m beam, 1.7 m height.
Side door with transverse garage
Found on yachts with a beach club aft, where the tender bay sits transverse to the centreline and launches sideways through a side door. The constraint is total beam of yacht minus the side garage encroachment from the opposite side. A tender 10 to 11 m long is feasible on yachts of 60 m and above with this arrangement.
Boat deck with overhead crane
The traditional arrangement on most 80 m and above yachts and on most explorer-style hulls. The tender lives uncovered or under a cradle cover on the boat deck, and a crane swings it overboard. There is no garage envelope as such; the constraint is crane SWL, deck loading, and visual impact when the tender is stowed. Tenders to 14 m and beyond live this way on the larger platforms.
Hybrid (garage plus boat deck)
On 70 m and above we increasingly see two tenders: a primary in the aft garage and a secondary or SOLAS unit on the boat deck. The brief decides which goes where. The SOLAS compliance guide covers the launch geometry the rescue tender requires.
For a single source of truth on which architecture suits which mothership size, see tender launch and recovery.
Working out the actual tender envelope
Manufacturers publish "LOA" but that figure does not tell the build manager what they need to know. Ask for these dimensions instead:
- Tender LOA on cradle, including engines and any swim platform extensions, with bow eye in stowage position.
- Maximum beam, measured at the widest point including rubrail, fenders if permanently rigged, and ladders.
- Beam at gunwale, where the boat actually sits in the cradle.
- Beam at waterline at static load (drives the cradle width).
- Height at maximum vertical point with hardtop deployed (T-top up, antenna installed, radar dome fitted).
- Height at minimum vertical point with hardtop folded or removed (drives the in-garage stowage height).
- Dry weight all-up, including engines, fuel reserve, and the full inventory.
These figures should be a contract schedule, not a marketing sheet. Yards including Pascoe, Wajer and Hodgdon supply detailed envelope drawings as standard. If a builder will not produce one, that tells you something.
The PSB Marine overview of tender garages makes the same point about millimetre-level tolerances; their typical 1.2 m height note is now the floor, not the ceiling, for serious garage briefs.
Cradle, rails, and the launching system
Once the tender envelope is fixed, the cradle and rails set the rest of the geometry. The choices in current production:
- Fixed cradle plus winch. Simplest, cheapest, requires the boat to be cinched down each transit. Common on smaller yachts and chase boats parked on a transom platform.
- Roller cradle on rails. Standard on flush garages. Works for tenders to about 9 m. Above that, the rails get heavy and the deck loading gets serious.
- Hydraulic platform. A lifting cradle on the garage sole that descends below the door sill and floats the tender off. Common on side-door arrangements and on most current 70 m and above flush garages.
- Float-in dock. The transverse arrangement on yachts like J'ade where the garage opens to the sea via a side door and the tender simply runs in. Constrains the tender to a low-air-draft hull.
A note on cradle SWL: design for tender weight at the upper end of the manufacturer's range, plus 15% for fuel, water, equipment, and build creep. A tender that is 8% over its design weight at delivery is normal. Twelve per cent is not unheard of.
Door geometry and float-out depth
The door has two jobs: to clear the tender envelope on the way out, and to allow the boat to float without grounding on the sill. Typical numbers:
- Door sill 150 to 250 mm above DWL at full design displacement.
- Door clear height 1.4 m for a 7 m tender; 1.6 m for a 9 m tender; 1.8 m for a 10.5 m hardtop.
- Door clear width 2.5 m for a 7 m tender; 2.9 m for a 9 m; 3.2 m for a 10.5 m.
The float-out depth (depth of water under the boat at the moment it leaves the cradle) needs to be at least 50% of the tender's static draft, plus margin for swell. For a 9 m limousine drawing 0.7 m at static load, that means at least 350 mm of water above the cradle when fully extended. On most modern hydraulic systems the cradle descends to 600 to 800 mm below the door sill.
Multi-tender garages and the SOLAS conflict
Yachts above 60 m increasingly carry more than one tender. The temptation is to nest them in a single garage, with a guest limousine on one rail and a sport tender on another. This works mechanically but it conflicts with the SOLAS launch time requirements if the SOLAS unit is one of the boats: you cannot guarantee a 5-minute launch if there is another tender in front of it.
The pragmatic spec on multi-tender yachts is:
- One garage dedicated to the primary guest tender with its own door.
- A second garage or boat deck cradle for the SOLAS rescue tender, with its own dedicated launch.
- A third stowage point (transom platform, bow garage, or boat deck) for the sport tender, Jet tenders, or chase boat.
Yachts under 60 m generally have to compromise. The honest brief picks one tender per garage and accepts the rest as deck or boat-deck stowage.
Future-proofing the envelope
Build cycles are 30 to 36 months. Tenders have a 5 to 10 year operating life. The yacht has a 25 to 40 year operating life. Garage sizing has to account for at least one and ideally two tender replacement cycles.
Three rules of thumb that have aged well:
- Add 200 mm to the LOA, 100 mm to the beam, and 100 mm to the height of the tender you actually want today. The next tender will be larger.
- Wire the garage for hybrid charging today even if today's tender is diesel jet. Charging infrastructure is the most common refit ask now.
- Specify the cradle SWL 20% above the current tender weight. The next tender will be heavier; battery weight is going one way only.
Yards that consistently get this right include builders with deep recent experience in the 60 to 90 m band and naval architecture practices that work on both yacht and tender sides of the brief. Where the yard or NA does not have that depth, bring in a tender consultant at concept stage.
Common garage sizing mistakes
- Sizing to a current production tender that will be replaced in three years. The garage outlives the boat. Size to the next generation.
- Forgetting the antenna and radar arrays. The hardtop folds; the GPS dome does not.
- Underestimating fender stowage. Permanent fender rails add 60 to 80 mm of beam.
- Designing the cradle for tender dry weight. Loaded weight is 12 to 18% higher.
- Locating the garage door drop below the swim platform. It looks elegant on the GA; it ships water in 1.5 m of swell.