CarRaft — Flood protection your car is already parked on

01 — The problem

Flood covers exist. They fail for a human reason.

Hurricane Harvey put an estimated half a million cars underwater. A single 2026 storm in Chiba, Japan flooded three thousand in one night. Car flood bags have been on the market for decades — and almost nobody had one deployed when it mattered.

Reason 1They're stored somewhere else

In the garage rafters, the closet, the trunk. When the warning hits at midnight in driving rain, nobody goes to dig out a 40-pound sheet.

Reason 2They take too long to set up

Unfold a tarp bigger than the car, drive onto it, raise the walls, zip the zippers, set the suction cups. Twenty minutes or more, usually two people.

Reason 3So people gamble

“Is it really going to flood this time?” The cover stays in its box for years — right through the one night it was bought for.

02 — The idea

Storage location = installation location.

That is the entire invention. The flood bag is already spread under your car, folded into the edges of the mat you park on every day. There is nothing to fetch, nothing to unfold, nothing to drive onto.

Cutaway view of the CarRaft mat with the flood bag folded inside its edge compartments

An ordinary mat, 364 days a year

A 15 mm three-piece rubber mat protects your garage floor and hides the entire waterproof bag in its side compartments. You drive on and off it like any parking mat.

A raft on day 365

Already in position. The bag's floor is permanently spread beneath the mat.
Self-closing slits. The walls pull out through elastic slits that close on their own.
No repacking ritual. Afterward, push the fabric back in. No folding required.

03 — How it works

Storm in the forecast? Three minutes, then sleep.

STEP 1Park on it, every day

The bag waits inside the mat's edges, shielded from sunlight and wear until the day it's needed.

Pulling the single cord raises the waterproof walls

STEP 2Pull one cord

The waterproof walls rise out of the slits on all four sides of the car at once.

Drawcord cinched below the windows, roof flap secured

STEP 3Cinch and cover

The drawcord tightens below the windows. The top flap goes over the roof and fastens on the far side.

Car floating inside the sealed CarRaft bag during a flood

STEP 4If the flood comes, it floats

Trapped air lifts the sealed bag — car, mat and all — while corner moorings hold it in place.

04 — Engineering

Nothing below the waterline but welded seams.

Cross-section drawing from the utility model application: bag stored inside the mat — Fig. 2 from the utility model application — stowed cross-section. Filed with the Japan Patent Office, August 2026.

One welded PVC pan underwater
Everything below the waterline is a single 0.5 mm PVC pan joined only by welding. No stitching means no needle holes to seep through.
Sewn joints ride above the water
The lightweight upper wall joins the pan 40 cm (16 in) above ground — higher than the floating waterline, where it never carries water pressure.
The closure sits at window height
The drawcord cinch rides about a meter above the water. It lives in the splash zone, not the pressure zone.
Stability by design
Internal ribs interrupt the free-surface effect known from naval architecture, and four corner moorings let the raft rise with the water without drifting.

05 — Specifications

Three sizes, compact to full-size SUV.

	S — Compact	M — Sedan / minivan	L — Full-size SUV
Footprint	13.8 × 6.2 ft 4.2 × 1.9 m	16.4 × 7.5 ft 5.0 × 2.3 m	19.0 × 8.2 ft 5.8 × 2.5 m
Mat	15 mm three-piece rubber mat, tapered drive-over edges, anti-slip surface
Hull (underwater)	0.5 mm UV-stabilized PVC tarpaulin, welded construction only
Upper wall & roof	75D PU-coated ripstop polyester (2,000 mm), sewn and seam-taped above the waterline
Closure	Perimeter drawcord with cord locks; roof flap with 50 mm hook-and-loop fastening
Mooring	Four corner loops — slide-loops for carport posts, or slack-line ground anchors
Deployment	About 3 minutes, one person. No tools, pump, or electricity

Values are design targets for the first production run and may be refined through prototype testing. Utility model registration applied for in Japan, August 2026.

06 — Reserve

Be first when the water rises.

$135planned launch price, size S · ¥19,800

Reservation is free and non-binding. You get launch pricing, first allocation from the initial production run, and footage from our flotation testing as it happens. Ships worldwide from Japan.

Distributors, retailers and press: we are selecting launch partners worldwide — North America, Europe, the Middle East, Asia-Pacific and Latin America. Use the form and choose “Distributor / trade”; we reply within two business days.

07 — FAQ

Fair questions.

Is it inflatable? Do I need a pump?

No. CarRaft is fully passive. The air already sealed inside the bag provides the buoyancy, the same way a ship's hull works. Nothing to inflate, charge, or maintain — and nothing to fail at 2 a.m.

My insurance covers flood damage. Why would I need this?

Comprehensive coverage pays out after your car is totaled. You still lose the car, wait weeks for a payout and replacement, and often see higher premiums. CarRaft is for keeping the car itself dry — insurance is for when that fails.

What about rain getting in the top?

The cinch and roof flap close the top against rain. The small amount that may get in pools at the bottom, where internal ribs keep it from sloshing and destabilizing the float. A drain port empties it afterward.

Won't the whole thing float away?

Four corner loops moor it. On a carport, sliding loops around the posts let it rise straight up with the water without drifting. Without posts, ground anchors with deliberately slack lines do the same job. It is never moored tight — that would hold it under.

How deep a flood can it handle?

Because the car floats, flood depth stops being the limit. In deeper water the raft simply rides higher, held in position by its moorings. What matters is freeboard — the closure sits about a meter above the waterline.

Can I really drive over it every day?

That is the design brief. The 6 mm wear surface is the same class of rubber used in commercial garage matting, and the tapered edges are made for daily tires. The bag stays protected inside until the day it earns its keep.