Seastead Housing Module Options & Analysis

Executive Summary

Decoupling the platform development from the housing module is an excellent strategy to reduce risk and cost. The primary challenges for your use-case are salt spray corrosion, weight constraints, and cyclic fatigue (constant motion, even at <0.1G, will cause rigid, non-marine joints to crack over years). Below is an analysis of available options based on your specific Caribbean market, 14'x60' footprint, and single-family requirements.

Option 1: The Caribbean Dream (Local Marine-Rated Solar Modules)

The Reality: Currently, there are no large-scale manufacturers based in the Caribbean that produce turnkey, highly-solarized, marine-grade modular homes. The Caribbean region generally imports these technologies from the US, Europe, or China due to higher local manufacturing costs and supply chain limits.

The Pivot: Instead of sourcing from within the Caribbean, your best bet is to import flat-pack or container-shippable units to your duty-free Caribbean shipyard. You will likely need to contract a 3rd party to install the "huge amounts of solar" either in China prior to shipping or at the assembly yard.

Option 2: Container-Shippable / Flat-Pack Housing

There is a massive industry in China building container-shippable flat-pack homes (often called "expandable container homes" or "prefab Apple Cabins"). Many can easily achieve your 14'x60' dimensions by linking modules.

Pros: Extremely cheap ($10,000 - $30,000 per unit). Designed to fit standard ISO shipping containers. Fast assembly.
Cons (Marine Context): Standard flat-packs use galvanized steel frames and cheap sandwich panels (EPS foam with thin steel skins). In a high salt-spray environment, these will rust rapidly. Furthermore, the hinges and joints on "folding" houses are not designed to withstand constant oceanic cyclic loading. They will squeak, leak, and eventually fail.

Recommendation for this route: If utilizing Chinese flat-packs, you must specify a custom build using aluminum framing and FRP (Fiberglass) coated sandwich panels instead of steel. You will also need your yard to heavily seal/weld the modules together once expanded, discarding the standard rubber gaskets which will leak from constant platform flexing.

Option 3: Surplus Offshore Oil & Gas Accommodation Modules

Offshore living quarters (often called "Accommodation Modules" or "Habitats") are heavily engineered for marine environments.

Pros: 100% marine rated, fireproof (A60 rating), excellent safety records, built to handle continuous motion and storms.
Cons: Extremely heavy (mostly thick steel). Designed as high-density crew dormitories (tiny rooms, communal bathrooms). Usually industrial and ugly. Tiny porthole windows.

Modifying for Single Family Use:

You can buy used modules from the US Gulf Coast (Louisiana/Texas) and transport them relatively cheaply to the Caribbean. However, modifying them for a family is difficult. Cutting through A60 structural steel to add large, family-friendly windows is expensive and requires marine-grade window inserts to maintain weatherproofing. Due to their extreme weight, they may require you to over-engineer your floating platform, negate any cost savings.

Option 4: FRP / Composite Sandwich Panels (The "Yacht" Approach)

Sourcing Fiberglass Reinforced Plastic (FRP) sandwich panels (usually a structural foam or honeycomb core sandwiched between fiberglass skins) from China is highly viable and represents the best intersection of weight, durability, and cost for a seastead.

Cost Estimate for a 14' x 60' Enclosure

For a basic 14'x60' box with a 10' ceiling height, you need roughly 3,200 sq ft of panels (floor, roof, 4 walls).

Item	Estimated Cost (From China)	Details
FRP Composite Panels	$12,000 - $25,000	$30-$70 per square meter, depending on foam core thickness (insulation) and fiberglass layup.
Shipping to Caribbean	$4,000 - $8,000	Flat panels stack incredibly efficiently. Will easily fit in one 40ft High Cube container.
Joining Materials (Epoxy, Glass Tape, Paint)	$5,000 - $10,000	Requires marine epoxy, biaxial fiberglass tape for seams, and marine topcoat (like Awlgrip or gelcoat).
Total Bare Envelope	$21,000 - $43,000	*Does not include windows, doors, interior fit-out, or solar.

Assembly Labor & Effort

While the materials are cheap, this is not a simple bolt-together process. It is effectively boat building. To assemble these panels, the shipyard must:

Setup a temporary jig to hold the large panels perfectly square.
Use structural adhesives to glue the panels together at the corners.
"Tape and glass" every seam inside and out using fiberglass fabric and epoxy/polyester resin.
"Fair" (sand and smooth) the joints, then paint the structure with UV-resistant marine paint to prevent the FRP from chalking in the Caribbean sun.

Fortunately, any shipyard in the Caribbean will have workers highly skilled in fiberglass and resin work. The result will be a lightweight, monolithic, waterproof box that handles motion beautifully because it can flex slightly without joints popping.

Final Recommendations & Next Steps

For Prototype/Testing: Look into the US Gulf Coast surplus market for an aluminum offshore accommodation module. It will be lighter than steel and natively marine-proof. It may not look like a single-family home, but it will allow you to test your 0.1G platform dynamics without spending money on custom architecture.
For Final Product (Best Cost/Performance): Pursue the FRP Composite Panel flat-pack. Work with a Chinese manufacturer that specializes in clean-room / cold-storage panels, but specify marine-grade gel-coated FRP skins instead of steel. Have them cut the window and door openings at the factory via CNC. Ship the flat panels to your Caribbean yard and pay local fiberglass workers to assemble and glass the seams.
Design Note on Windows: A single-family home needs large windows. In a marine environment subject to constant flexing, large residential glass will shatter. You must use flexible marine glazing (like Makrolon/polycarbonate) or specifically engineered marine framed windows (like those from Diamond Sea Glaze or Lewmar) that allow the glass to float within rubber gaskets as the house twists.