Definition
The mothership is the primary yacht from which one or more tenders, chase boats, or support craft are launched, recovered, fuelled, and crewed during a programme.
Background and use
In tender and chase-boat work, "mothership" is the reference point for almost every specification decision. Garage door openings, davit SWL, helideck clearances, and crew accommodation on the yacht all set the envelope for what the tender programme can look like. A 60 m motor yacht with a single 7 m garage opening has a very different tender fleet than a 90 m explorer with a side-loading bay and a foredeck crane.
The relationship is operational as well as physical. The mothership's bunkering schedule, watch rotation, and itinerary all flow into the tender programme. A chase boat that runs 200 nm a day on diving charters needs fuel, fresh water, and parts staged from the mothership's stores; the engineer who maintains the tender outboards is usually a yacht crew member, not a separate hire.
For larger programmes a shadow vessel takes on much of this load, but for the majority of yachts in the 40 to 80 m range, the mothership is the only support platform the tenders ever see.
Related considerations
- Garage door dimensions are usually the binding constraint on tender length and beam.
- Davit SWL and reach drive both tender weight and stowed location.
- Crew berths on the yacht limit how many dedicated tender drivers are realistic.
- Bunker capacity sets the practical range of high-fuel-burn chase work.
- Yacht class notation (PYC, LY3, commercial) governs how tenders may be used.