Surveyor's Corner

Welcome to the ACE Recreational Marine Insurance Online Surveyor's Corner

We at ACE are pleased to share this new online and interactive resource to assist you in keeping your boat or yacht in ship shape condition.  Through decades of experience surveying boats and yachts of all sizes, ACE's Marine Advisory Services team of marine engineers and surveyors has developed a collective expertise that is unmatched in the marine insurance industry.

You'll want to visit the ACE online Surveyor's Corner often to read their latest useful tips for maintaining and servicing your vessel, gathered from years of actual surveying scenarios.

Category: Fire Safety

Topic: When is Gasoline Safer than Diesel?

Boaters have always heard that gasoline engines aren’t as safe as diesel engines because gasoline vapors are dangerously explosive and diesel vapors aren’t.  But there’s one instance where diesel-powered boats pose a greater risk of explosion than gas-powered boats!

We know that gasoline vapor is an explosion risk on boats.  That risk has led to Federal regulations that require safeguards in gasoline engine spaces: ventilation blowers, ignition-protected electrical systems and flame arrestors on carburetor intakes.*  

None of these items are required in diesel engine spaces.

So, where’s the added risk on diesel-powered boats?  It’s present if the boat has propane aboard.  Propane (LPG) vapor is heavier than air and if there’s a leak, it will flow downhill to the lowest point in the boat which is often the bilge in the engine space.

Starter motors, alternators and generators, some voltage regulators and many other electrical devices in a diesel engine space can produce sparks, and if there’s propane vapor present, those sparks could ignite it, with disastrous results.

This means that a properly maintained gasoline-powered boat may actually be safer in the event of a propane leak than a diesel-powered boat.  That’s one more reason why it’s so important to make sure your boat’s propane system is correctly and safely installed, and in good condition!

*33CFR, Subpart I, Section 183; 33CFR, Subpart J, Sections 183.501-183.590; 33CFR, Subpart K, Sections 183.601-183.630.