Dream project: Converting a support vessel <300 GT into a long-range liveaboard expedition yacht

[Josef Brychta]

Hi @gonzo ,

Really appreciate your message — it’s refreshing to finally see people here who are willing to talk, not just shout “can’t be done” from the sidelines.

This project has been in the making for nearly 2 years.
Every requirement, hardware, software, and risk factor has been dissected from all possible angles — multiple times.
My SOR (Statement of Requirements) is now over 40 pages long and keeps growing.

Truth is, risks can never be fully eliminated — not at sea, not on land, not anywhere.
At the end of the day, it comes down to the individual:
Some people freeze when the match won’t light — others figure out how to spark a fire.

Thanks again for the grounded input — it means a lot.

Best regards,
Josef

 

[Ad Hoc]

What I don't see in any of the debates and exchanges of "ideas" and "issues", is a budget.
What is your budget for this project?

 

[Josef Brychta]

Hi @Varn ,

Thanks again — truly appreciate your thoughtful engagement. You're spot on that this is well past "yacht thinking" and deep into expedition-grade systems. Glad it shows.

Passive cooling in the dry store
Yes, I’ve seen that method used — passive bleed from the freezer/fridge loop via dampers or ducting. It’s a clever approach with low energy draw. On my side, I’m still weighing it against active ventilation, especially because I’m targeting strict humidity control in that zone (for flour, rice, powdered goods). Passive bleed might work in moderate zones, but in the tropics or Red Sea, I’m leaning toward a dedicated low-power active system for stability. Insulation profile will be key.

Cooling system: Glycol vs. compressor per zone
Very much leaning toward a glycol loop — centralized chilled liquid circuit feeding all cold zones (walk-in freezer, fridge, veg hold). It reduces the number of moving parts and allows for centralized diagnostics, redundancy, and heat dumping control, especially when integrating with solar load management. The loop would be driven by one or two variable-speed chillers (possibly Seawater-cooled), depending on final loads and available power.

Fire detection/suppression in cold rooms
Yes, planning to integrate thermal detection (FLIR or thermal probes) into the fridge/freezer rooms, along with gas-based fire suppression (likely Novec 1230 or similar). I’m well aware of the risks of overloaded circuits, compressor failures, or insulation outgassing — especially in long-range, unattended scenarios. Fire risk isn’t limited to engine rooms anymore.

Fridge/freezer diagnostics into Maretron
Correct — I’m feeding real-time temp data, door open states, defrost cycles, and power draw via Maretron DSM/N2K integration, so I can monitor anomalies even remotely (especially with Starlink + QNAP as backbone). I'm also exploring full thermal load monitoring — if sensors allow — to catch degrading insulation or compressor inefficiencies early.

System sketch
You're right — this is heading toward a research-grade platform, just without the scientists. I’ll try to post a basic block diagram or sketch once the layout is finalized. My goal is full situational awareness, operational autonomy, and minimal guesswork even weeks out at sea.

Appreciate you following along — these kinds of exchanges are exactly what help refine the vision. And as always — feel free to throw in more thoughts or critiques. It’s rare to get quality dialog in this space.

Best regards,
Josef

 

[Josef Brychta]

@Ad Hoc

Appreciate the question — and yes, budget is always a core parameter.
However, at this stage, I'm primarily exploring platform feasibility, operational logic, and system integration — with the goal of aligning the design with long-term liveaboard and expedition use.

The budget is defined, but not something I plan to disclose in a public thread — particularly since it's a variable based on whether I proceed with a refit or a new build.

Once the platform is locked in, I'm happy to go deeper into the economics of build vs. refit — ideally with the right yard and technical partners on board.

 

[Ad Hoc]

....The budget is defined, but not something I plan to disclose in a public thread — ...

Understood and noted.
But this means you'll continue to get replies like you have, since it is "just an idea" without focus.
Money creates the focus,....not endless ways of how it can be done, with endless words.

 

[Josef Brychta]

@Ad Hoc
Fair point — but I respectfully disagree with the notion that money creates the focus.
In serious expedition projects, it's the operational scope and risk profile that define the architecture — not the other way around.

I've spent two years working through the technical, safety, and lifestyle parameters to shape a very clear Statement of Requirements. The budget exists to support that — not to dictate it.

When the time comes to bring a naval architect onboard in a professional capacity, all the financials will be presented and discussed in full transparency — just not in a thread shared with anonymous armchair critics.

 

[Varn]

Hey Josef,

The way you're building in redundancy and autonomy especially around cold storage and fire detection, makes it very clear this isn’t just theory. It’s a grounded, system-driven project, even if you’re still between platforms.

Your plan to run a glycol loop with dual chillers, passive vs. active ventilation logic, and full N2K integration for diagnostics… that's the kind of detail you usually only see in research vessels or commercial support ships. The fact you're packaging it into a sub-300 GT, owner-operated platform makes it even more compelling.

The fire suppression in cold rooms is something I hadn’t thought about until now — and you're right: those zones are increasingly energy-dense, especially with variable-speed compressors and battery backup in play.

Looking forward to that system sketch when you’re ready — even a simple block diagram would be fascinating to see.

Thanks for keeping the thread focused on engineering, not just opinion.

VARN

 

[Ad Hoc]

...Fair point — but I respectfully disagree with the notion that money creates the focus.....

That's where you and I differ.
Money is the focus of everything in design, from a professional point of view.
The other way around is the point of view of amateurs, who are not involved in the day to day business of boat/shipbuilding, only ideas.
Different perspectives and objectives.

Good luck...

 

[Josef Brychta]

Hi @Varn ,

Really appreciate your words — especially from someone who's clearly been around real-world systems and understands the nuances beyond just shiny renderings.

Yes, the fire suppression aspect in cold storage was a later-stage realization for me as well. The more I explored the idea of backup power, thermal inertia, and even compressor heat rejection profiles, the clearer it became that these “quiet” compartments can turn into hotspots fast under failure conditions. Gas-based suppression (like Novec 1230) in sealed cold zones is currently my preferred direction — zero residue, fast response, and safe for electronics.

The system sketch is definitely coming — once I finalize the baseline layout (Miss Sarah J or extended platform), I’ll put together a first-pass architecture diagram. I’m also considering how to modularize the system zones for maintenance isolation and partial operation, in case of failure during long passages.

Glad to have someone here who values logic over drama.
Thanks again for the encouragement.

Josef

 

[Josef Brychta]

Hey @Varn ,

Originally, I spent quite a bit of time exploring Bering platforms — they’re very well-engineered and built for serious expedition work. But something was always missing on the operational side, especially when it came to provisioning and internal access.

That’s exactly what caught my attention with INACE and especially Miss Sarah J. The moment I saw the underdeck access hatch — where you can lower heavy provisions directly from the dock onto the main deck and then drop them by crane straight into the storage zone below — I was sold. It’s such a smart, real-world solution for autonomous cruising.

I instantly fell in love with that layout. Add to that a small lift to move supplies from the dry store up into the galley — and suddenly you’re not just planning a trip, you’re planning how to thrive onboard.

Bonus? The forward crew cabins, accessible from the main deck, are easily convertible into a sauna and steam room. Honestly, what more could I wish for?

Josef

 

[Josef Brychta]

By the way — feel free to check out my gallery here:
https://www.boatdesign.net/gallery/users/josef-brychta.86776/

It includes both the original and modified deck plans.
Areas marked 1, 2, and 3 are designated for storage (freezer, fridge, dry store), and area 4 was originally the forward crew quarters — which I plan to convert into a sauna and steam room.

Right now, I’m waiting to hear back from Kirschstein Designs Ltd. to get a clearer picture of how everything could fit together.
Based on all calculations so far, Miss Sarah J — as beautiful as she is — seems a bit too small.
To accommodate all requirements properly, I’m realistically looking at a platform in the 31–33 meter range.

Still, it gives a good sense of the concept and direction I’m heading.

Josef

 

[Rumars]

At this stage, the layout that suits me best is based on Miss Sarah J. I’ve studied a wide range of vessels and concepts, and while I found another larger model from the same designer, that one is unfortunately too big for my needs (and registration strategy).

Could you please explain why the Inace Explorer 105 is too big for you if what you want is an Inace Explorer 95 "but ideally longer"?
As for registration strategy the boat is advertised as 230GT, well under your 300GT limit.
Currently Victoria A is for sale, I recommend you take a trip to Rio. VICTORIA A Yacht for Sale in Brazil | 105' (32.28m) 2006 INACE | N&J https://www.northropandjohnson.com/yachts-for-sale/victoria-a-105-inace

 

[Josef Brychta]

Thanks @Rumars — yes, Victoria A is actually one of the yachts I’ve been seriously considering.

When I said “too big,” I wasn’t referring to her, but rather to the Inace 126' Aft House Explorer, which is still under construction — and whose GT isn’t even finalized yet. That platform already stretches beyond what I need — both in length and complexity.

I keep referring to Miss Sarah J because her refit includes something quite important for me: a dedicated hatch from the deck directly into the storage hold, which allows provisioning to be lowered straight from the dock to the storerooms by onboard crane. It’s a small detail, but makes a big operational difference for my use case.

As I’ve mentioned before, I’m not looking for anything I won’t truly use.
Efficiency, autonomy, and simplicity remain my core priorities.

 

[Varn]

Hey Josef,

Just caught up on your recent posts and took a look at the gallery. It's clear your layout is shaped around how you plan to actually live and operate on board, which is refreshing to see.

That underdeck hatch setup caught my eye as well. I’ve come across similar concepts on support and survey vessels — and also in my current work with Ro-Ro/Con-Ro ships, where efficient vertical loading and internal logistics are a big part of operations. Translating that into a smaller, private platform makes a lot of sense, especially when autonomy is the goal.

The Novec suppression choice also resonated with me. I’ve seen that used in sealed compartments and unmanned control spaces, where traditional methods aren’t practical. Cold zones definitely fall into that category if airflow stops or if compressor heat builds up.

I don’t have deep at-sea experience myself, but coming from a machinery and port operations background, I’ve got a real interest in how systems like this can be adapted smartly for smaller vessels.

— VARN

 

[fallguy]

@fallguy

At this point, I honestly wonder what you’re doing on a boat design forum.

Your posts are not about constructive critique — they’re about telling people why things can’t be done, even when others clearly state how they plan to do them. You dismiss modern engineering, proven solutions, and even professional design processes, only to push your own fearful worldview.

Let me remind you: thousands of boats operate safely with just one or two people aboard — including ocean crossings and circumnavigations. Single-handed sailing is not a myth. What matters is preparation, equipment, and good seamanship. Not fear.

If your contribution to this forum is limited to telling people their projects are doomed, then maybe it’s time to ask yourself why you’re here.

Some of us are building yachts — you’re just building walls.

I built a small yacht.

No need to be offensive.