How water resistant is a typical yacht nav & comms installation?

Given the cost of properly stranded, tinned copper cable it's not surprising to me that builders use a lot of bare solid copper. These are routinely double or tripple the cost. I agree that these shouldn't find there way into ocean-going boats, but given the usage profile of a more typical sailor these cables and connectors will easily last the lifespan of the rest of the boat. Properly strapping cable runs greatly reduces vibration failures, and making enclosures that are weather tight or heated (even passively) keeps moisture at bay. The problems come when higher spec are not used in the more demanding circumstances.

Deck connectors are another matter. I have installed a few Raymarine units into trailered sailboats, and have tried in vane to find a good marine deck connector for the 5-pole cable used by the masthead wind sensors and have instead needed to resort to military connectors to find the combination of water proofing and longevity.

The same story can be told in road trailers - the person that decided that the Bell Jar principle was sufficient to keep your lights working never considered turbulent spray at highway speed. Today's LED lamps are much improved, but we've lived with a lot of junk for a long time.

I'll point a finger at the buying public here, too. Nobody seems to dig under the hood much these days, and many buyers will choose style over substance, or be deterred by the expence of doing the job correctly.

"I'll point a finger at the buying public here, too. Nobody seems to dig under the hood much these days, and many buyers will choose style over substance, or be deterred by the expence of doing the job correctly."

I wonder how many even know what to look for. Is the industry guilty of failing to educate the buyers? If the domestic hi-fi industry can persuade people to buy gold-plated connectors for fiber-optic cables, surely the marine equipment industry can convince boating folk that it's worth specifying genuinely appropriate connectors. 

However, I take your point about the components on offer from the industry. Perhaps it's planned obsolescence. Maybe there's a niche here for someone.

Mil Spec? If a boating environment doesn't justify Mil Spec, what does? It should be part of the industry's quality standards.

OK, I'll accept that the guys cruising round the Solent and doing hlaf-a-dozen trips across to France (or their equivalent in Chesapeake Bay or San Francisco) can get away with checking everything at the end of each season - most of the time. But what kind of money are we talking about, in comparison with the cost of the kit?

I'll bet everyone is glad to see LEDs replacing  tungsten filaments, but my memories of wiring that goes up masts  (to wind vanes an danemometers as well as lights) is that connectors had lousy waterproofing at entry points, and inadequate or non-existent strain relief. I know you're not meant to pull on the fittngs, but the top of the mast shakes around, and the connector at the bottom is often in a place where it gets bumped into.