Insurance Coverage

[PmacOC]

I'm new to this forum and glad to be here. I see we have a sponsor who sells boat insurance and I'll call Vito straight away, but I'd like some help in determining the best comprehensive coverage to get. Last summer a stainless steel plug on the top of the engine of my 2003 SeaRay failed and as a result a constant stream of water shot out of a hole in the plug and into the intake manifold ruining the engine. Both my marina and my Progressive insurance adjuster said they had never seen a stainless steel plug like this fail, but Progressive denied my claim. When I read my policy, the comprehensive section covers almost nothing. My boat was meticulously maintained and this bad part resulted in a catastrophic engine loss. Something like this should have been covered, but it wasn't. Does anyone know of how I should make sure my next policy protects me more fully? Thanks in advance for your help.