Hi - I'm a writer and a total rookie when it comes to all things yacht! My story takes place on a superyacht where the ship experiences a blackout and loses comms, GPS, etc.

While there are obviously several things that could lead to an outage or a fault with the main switchboard, doesn't the emergency diesel generator automatically kick in? Therefore powering the emergency switchboard and restoring all comms, GPS, radios, etc? If so, this would create a plot hole in my story. So - my main question is:

Are there ever circumstances in which ships lose both the main and emergency switchboards?

If so - how does that happen? Or how could this happen?

At that point, I believe the main device you would have left in terms of rescue is your EPIRB, but perhaps there are additional rescue devices I'm not thinking of.

Thank you all for your answers, really appreciate it.

I recently saw the Al Lusail Lurssen super yacht owned by the Qatar emir. And my question is genuinely what can I do on a yacht, I guess it's a good object to have it's fun but genuinely it's just a moving home.

If there are other yacht owners or people that spend time on yachts what do you do with your yacht ?

TL;DR: The "10% of purchase price per year" rule that gets thrown around in yachting circles is outdated nonsense. Real numbers are 4–7.5% depending on size and location. Also: buying used doesn't save you money the way you think it does, and chartering to "cover costs" usually doesn't work.

I've been working in the Monaco/Côte d'Azur yacht market for years, and I got tired of people making multi-million euro purchase decisions based on a rule of thumb from the 1980s. So I put together a full breakdown.

The setup

I analyzed four real yachts across two markets (Miami/Biscayne Bay and the French Riviera). Every cost category: marina fees, insurance, engine service, haul-out, antifouling, detailing, comms, seasonal logistics. Nothing left out.

The four boats:

• Pirelli 42 (13m, ~$900k) — outboard sportboat, zero permanent crew
• Azimut 53 (17m, ~$1.6M) — owner-operator flybridge
• Princess F65 (20m, ~$3.5M) — semi-professional operation
• Ferretti 860 (27m, ~$7M) — full superyacht with year-round crew

The actual numbers

Boat	Miami OPEX/yr	French Riviera OPEX/yr	% of value
Pirelli 42	$43,710	€27,250	4–5%
Azimut 53	$82,440	€61,950	~5%
Princess F65	$151,800	€116,100	4.5–5.5%
Ferretti 860	$511,000	€361,800	6.5–7.5%

Not a single one hits 10%. Even the Ferretti 860 — a full superyacht with 2–3 year-round crew — comes in at 6.5–7.5% on the Florida market, and 5–5.5% in Europe.

Why Miami is so much more expensive

Insurance is the main driver. After hurricanes Harvey, Irma and Maria in 2017, underwriters went nuclear on Florida rates. A $900k Pirelli 42 in Miami: $18,000/year in insurance. Same boat on the Riviera: €9,000. Florida also has 3.3 lightning strikes per 1,000 boats annually. That's just a fact.

For the Ferretti 860 the difference is brutal: $125,000/year for insurance in Miami vs. €64,000 on the French Riviera.

Geography isn't a preference — it's a financial variable.

The used boat trap

Here's where it gets interesting. A 2010 Azimut 53 costs €300–350k today (down from ~€1.6M new). Looks like an incredible deal. You "saved" over a million euros.

Except your annual running costs are nearly identical to a new one: €58,000–92,000/year. Why? Because you also need a repair reserve — a separate budget line of €20,000–35,000/year that doesn't exist for new boats.

The Volvo Penta IPS 950 drive system is the critical piece:

• Shaft seals need replacement every 500–1,000 engine hours (not every year — every hour interval)
• If water intrudes into the gearbox (happens silently over months), you're looking at €25,000–65,000 to rebuild one pod
• New factory pod: €90,000–115,000 each. Two pods on an Azimut 53.
• Detection method: lab oil analysis (~€500). Cost of skipping it: potentially more than the boat is worth.

The only way to avoid buying someone else's hidden problems: independent pre-purchase survey with ultrasonic hull scanning and oil analysis. Cost: €3,000–7,000. For a €350k boat, this is non-negotiable.

"I'll charter it to cover costs" — does it work?

Short answer: not really, and on a used boat, almost never.

Here's the math on an 8-week charter season with an Azimut 53:

Item	Amount
Gross charter revenue	+€72,000
Agency commission (25–30%)	−€18,000–22,000
Seasonal captain + benefits	−€18,000–26,000
Operating costs + APA	−€8,000–14,000
Accelerated service + repairs	−€12,000–23,000
Net result	−€4,000 to +€16,000

And that's with NO major breakdown. One IPS pod failure wipes out the entire season and then some.

Charter doesn't lower your costs — it accelerates wear on every system onboard and raises your repair budget. The IPS shaft seals that need replacement every 500–1,000 engine hours? A charter season adds 800–1,200 hours. Do the math on how many service cycles that compresses.

MAN engines: an important distinction

If you're looking at used boats with MAN diesels (common in Princess, Ferretti, Sunseeker), production year matters enormously.

Pre-2018 MAN common rail engines use a tank-and-bundle heat exchanger. Full cooling system service required every 2 years. Cost for a V8 1200: approximately €16,000–22,000 per service cycle.

Post-2018 MAN switched to a plate heat exchanger. Service interval: every 4 years. Same engine family, completely different maintenance bill.

If you're buying a used boat with pre-2018 MAN engines, the first question is: when was the last A1 service done? If there's no documentation — budget for it in year one.

Bottom line: three things to know before buying

1. Calculate OPEX, not percentage. Get local marina rates, local insurance quotes, local service costs for your specific engine. The 10% rule tells you nothing useful.
2. Independent survey is non-negotiable for used boats. Not the seller's survey. Not the broker's "we had it checked." Your own independent marine surveyor, with ultrasonic hull scan and oil analysis of the drive system.
3. Geography is a financial decision. The Riviera generates 24–38% lower OPEX than Florida depending on the class of boat. For a Ferretti 860, that's roughly €150,000/year difference. That's not a lifestyle choice — that's a financial parameter.

Happy to answer questions. Have the full breakdown with all cost tables as a PDF if anyone wants it.

I don’t merely mean assembly time, I mean total man hours all the way down to the gathering of resources, production and delivery of each individual component.

I’m not expecting a precise answer by any means but I’m curious at what order of magnitude the answer lies.