Why garage sizing is the constraint that decides everything
Tender selection on a new build or a refit usually comes down to the geometry of the tender garage, not the wish list. A garage door 8.2m wide with 2.4m headroom rules out roughly half the credible 9-10m candidates before any other criteria apply. Get the garage envelope wrong at general arrangement stage and you spend the rest of the build trimming the brief to fit.
This page is the working reference. The tender specification guide sets out the buyer's full check list; this one is the geometry.
The four binding dimensions
Every tender garage has four constraints, in order of how often they bind:
- Door aperture (width and height): the boat must fit through the opening with the lifting strops on
- Internal length: the boat plus deployed bow eye and stern eye fittings must clear the bulkheads
- Internal width at maximum beam point: the hull's widest section at the height it sits in the garage
- Crane reach and SWL: the lifting gear has to actually pick the boat up and swing it clear
Any one of these failing is a no-go. The order matters because a boat can be specified slightly shorter to clear length, but no amount of negotiation makes it narrower than its beam.
Allowance for fendering, lifting strops, and clearance
The naked dimensions on a builder's drawing are not the dimensions you measure for fit. Add:
- 80-150mm each side for permanent fendering or D-section rubbing strake
- 100-200mm for the lifting strop loop above the boat (varies by crane type)
- 200-300mm minimum vertical clearance under the deckhead for safe handling
- 100-200mm clearance to the bulkheads at each end for safe stowage in a seaway
A boat that nominally measures 9.0m LOA and 2.6m beam needs roughly a 9.4m by 2.9m clear envelope, with 300mm-plus headroom over the highest point of the boat (typically the windscreen on a sport tender, the radar arch on a limousine). This is why "9m by 3m" garages routinely accept only 8.5m boats in practice.
Typical garage envelopes by mothership LOA
These are working ranges, not standards. Every yacht is a special case.
| Mothership LOA | Typical garage door | Typical internal length | Typical clear height |
|---|---|---|---|
| 40-50m | 5.5-7.5m wide x 2.0-2.4m | 6-8m | 2.0-2.5m |
| 50-60m | 7.0-8.5m wide x 2.2-2.6m | 7-9m | 2.2-2.7m |
| 60-80m | 7.5-10m wide x 2.4-2.8m | 8-11m | 2.4-2.9m |
| 80-100m | 8-12m wide x 2.6-3.2m | 10-13m | 2.6-3.2m |
| 100m-plus | 10m-plus wide x 3m-plus | 12m-plus | 3m-plus |
These envelopes also have to accommodate jet skis, dive gear, and water-sports kit on the same deck on most yachts, so the clear length usable for the primary tender is often less than the garage's gross length.
Foredeck and aft-deck stowage alternatives
Not every tender lives in a garage. Three other options:
- Foredeck stowage under a removable hatch or in a recessed pit, with a deck crane. Common for limousine tenders on motor yachts where the aft is reserved for guest space
- Aft deck open stowage under the helideck or on a dedicated platform, with a stern davit or A-frame
- Side garage in the hull, opening from the side, increasingly common on yachts above 70m
Each has a different geometry constraint set. Side garages are the most flexible but the most expensive to engineer, and they take displacement out of the hull form. Aft-deck open stowage exposes the tender to weather and salt; expect higher maintenance burden.
Crane geometry and SWL
The crane has to reach over the side of the yacht with the boat suspended, deposit it in the water clear of the hull, and recover it without swinging into the topsides. Three crane types:
- Knuckle-boom crane: the standard for tender garages, extending and folding within the garage envelope. SWL typically 2,000-6,000kg
- Telescopic crane: longer reach, used for foredeck stowage where the boat has to clear the bow flare. SWL up to 10,000kg-plus on larger yachts
- Davit (single or double point): simpler, lighter, used on smaller yachts and for SOLAS rescue tenders that must launch quickly
Tender weight at lift includes the boat, fuel (full or partial), water, gear, and the lifting bridle. Always size SWL to at least 1.25x dry tender weight to allow for full fuel and reasonable safety margin. For a 9m sport tender at 3,200kg dry, plan on a crane SWL of at least 4,000kg.
The classification rules require the crane to be load-tested and certificated, with annual thorough examination.
Lifting points on the tender
The boat-side of the equation:
- Two-point lift (bow and stern eye) is the dominant pattern for tenders up to 10m
- Four-point lift (typically two strop attachments per side) for larger tenders and for boats lifted in a heavy seaway
- Lift points must be load-rated, proof-tested, and certificated. Drop-tested with documentation that follows the boat for life
Lifting points are a structural feature designed in at moulding stage. Retrofitting load-rated lifting points to a tender that wasn't designed for it is possible but expensive and limited. Buy a tender that was engineered for the lift type your mothership uses.
Headroom and the windscreen problem
The most-frequent fit failure is windscreen height on limousine tenders and tall sport tenders. The boat measures fine on the LOA and beam but the windscreen catches the deckhead. Fixes:
- Folding or removable windscreen (engineered cost, weather sealing complications)
- Removable radar arch
- Drop-down hardtop, increasingly available on tier-one builds
- Specify a boat with a lower profile
For boats in the 9-12m bracket where headroom is tight, get a CAD overlay of the boat in the garage at full garage stowage geometry before contract.
Beam at the chine vs maximum beam
A common tolerance miss: builders' drawings show maximum beam at the gunwale, but the boat sits in the garage on its hull at the chine. The chine beam is narrower; the hull may swell out above the chine to a wider deck-edge measurement. The hull cradle has to support the boat at the right point, and the deck-edge clearance matters separately for crane handling.
Always work from the builder's full set of section views, not just the GA.
Trolley, cradle, or wet stow
Three stowage approaches inside the garage:
- Cradle on rails: the boat sits on a wheeled cradle that runs out on rails before lifting. Common on smaller yachts
- Air-cushion or pad stow: the boat sits on weight-distributing pads, lifted directly by the crane. Cleaner solution, more expensive
- Wet stow on a swim platform-integrated dock: the boat floats in a wet garage that opens to the sea. Used on some larger yachts and on dedicated shadow vessels
Cradle systems impose extra height and width constraints (the cradle adds 100-200mm under the keel and the rails take width from the garage floor). Account for these at the brief stage.
Designing tender selection backwards from the garage
The honest workflow on a new yacht build:
- Draft the GA with target tender(s) defined by category and approximate dimensions
- Confirm the tender garage envelope with the naval architect, including clearances
- Build the candidate tender list against the actual envelope, not the headline figures
- Pick the tender, then re-verify garage fit with the tender builder's full drawings before keel laying
- Re-verify on first crane test on the actual mothership before delivery
Cutting steps 4 and 5 has cost owners six-figure refit invoices to widen garage doors after delivery. It is not unheard of for a yard to deliver a yacht with a garage that the chosen tender will not actually fit.
When the garage is the wrong place to put the boat
If the garage forces a tender choice that compromises the brief (forced to accept lower capacity, lower performance, smaller boat than required), the right answer may be:
- Add a second smaller tender in the garage for short transfers, plus a chase boat running independently for the longer-range work
- Move the tender out of the garage and onto a foredeck or aft cradle, accepting the weather exposure
- Rework the GA at refit to expand the garage (achievable on some hulls, prohibitive on others)
For a specific garage and a specific operating brief, send us the dimensions and we will return a vetted tender shortlist that actually fits.