I turned the key on the first warm day of spring, and instead of a roar, I heard a sickening gurgle. I opened the engine hatch to find a slurry of oil and water in the bilgeāthe engine block had cracked down the side. I filed a claim immediately, admitting I did the winterization myself in my driveway. The adjuster asked one question: “Do you have a receipt for the antifreeze?” I didn’t. They denied the $25,000 re-power claim the next day.
Key Takeaways
- The “Freezing Exclusion” is Standard: Most marine policies exclude damage caused by freezing or ice unless you can prove you took reasonable care to winterize the vessel.
- DIY is High Risk: If you winterize yourself, the burden of proof is on you. If you miss a drain plug or the thermostat blocked the antifreeze, it is considered “faulty workmanship” or negligence, which is excluded.
- Professional Winterization is Insurance: Paying a yard to do it transfers the liability. If the block cracks after a pro did it, their “Garagekeepers Liability” pays, or your insurance pays and subrogates (sues) them.
- The Date Matters: If the damage happened during a “lay-up” period defined in your policy (e.g., Nov 1 – April 1), but you were still using the boat in December, coverage is void.
The “Why” (The Trap)
The trap is “Lack of Proof.”
Insurers know that engine blocks don’t crack if properly drained and filled with propylene glycol. Therefore, a cracked block is prima facie evidence of improper winterization.
Without a receipt from a mechanic, it is your word against physics. In 2026, AI claims adjusters automatically flag “Freezing” claims for denial unless a “Winterization Invoice” is attached to the file.
The Investigation (I Called Them)
I asked claims managers how they handle “Cracked Block” claims.
BoatUS (Geico Marine)
- Policy: They are generally one of the fairest. If you bought the “Ice and Freezing” coverage (an add-on), they pay even if you did it yourself, provided you can show receipts for the materials (antifreeze/fogging oil).
- The Catch: You must have purchased the specific rider.
Progressive
- Policy: Strict. If you cannot prove professional winterization, they often classify it as “wear and tear” or “lack of maintenance.”
- My Analysis: Do not DIY if you have Progressive unless you video record the process.
Local Marina (The Pro)
- Liability: I asked a marina manager. “If we winterize it and it cracks, we buy you a new engine. That’s part of the $400 fee.”
Comparison Table
| Winterization Method | Cost | Insurance Risk | Liability Holder |
| DIY (No Proof) | $50 | Extreme | You |
| DIY (Video/Receipts) | $50 | Medium | You (Must prove it) |
| Professional Yard | $400+ | Low | The Yard |
| Heated Storage | | Low | Storage Facility |
Step-by-Step Action Plan
- Hire a Pro: If your boat is worth >$50k, the risk of a $20k engine loss isn’t worth saving $300.
- Save the Work Order: Ensure the invoice says “Winterize Engine” explicitly.
- [IMAGE: Photo of a marina invoice itemizing ‘Winterization Service’]
- If DIY, Video It: If you must do it yourself, set up your phone. Record yourself pouring the pink (RV/Marine) antifreeze into the strainer until it exits the exhaust pure pink. Keep the receipt for the gallons used.
- Check the “Lay-up” Dates: Ensure you don’t start the engine before the “Commissioning” date listed in your policy, or you risk voiding the freeze coverage.
FAQ
Does a bilge heater count?
No. If the power goes out (which happens in ice storms), the heater fails, and the block cracks. Insurers do not accept a “bilge heater” as proper winterization.
What if I live in Florida?
You usually don’t have a freezing exclusion, but if a freak frost hits, you are expected to take “reasonable care.”