I think I mentioned my planned route in another thread. We're considering coming up from the south because we want to do Bar Harbor. We could then head around to pick up your route, but it takes us significantly out of our way. In the twin, I'd have no problems doing the 57NM across the bay, but it's something I will definitely be thinking about in the 182.
I've done longer overwater in that plane, but that was the Bahamas, where the water is slightly warmer! Who knows, maybe Leslie and I will take the opportunity to get instruction in the 310 and get our multi ratings! (Of course then we'd still be on a single engine over the water, because most training for the multi is done with only one working!
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Let's look up the gliding range of the 182:
Somewhere around 11 NM at 8000, maybe 14 NM at 10,000.
So, for no wind conditions, you have 57 NM - 22 NM for 35 NM when your out of gliding range of land.
35 NM is maybe 20 min or less in a 182, at 8000 feet.
So, for your worst case scenario, you have a 20 minute window for a catastrophic engine failure (complete failure, not a partial power loss) where you'll go swimming. Every minute gets you at least 2 NM closer to shore.
Your risk decision should be based on:
The likelihood of being completely surprised during that window (no rising oil temp, no roughness, etc) and having a failure.
The impact of the failure - in winter, you're gonna die, almost certainly, unless you fly in a gumby suit. In summer, with good life jackets, you'll probably be OK, since you'll have time to call mayday and there are generally pleasure craft out for you to ditch nearby.
So you have your risk and impact. What can you do to mitigate the risks and impact?
Engine Monitor, Good Maintenance, close attention to detail, will all lower your risk, since you'll probably catch a problem early enough to abort the crossing.
A life raft, PLB (406 MHz), and survival gear would reduce the impact. Having family on board may increase the impact.
Of course, nobody can define what your "accept/deny" level of residual risk will be. This was just more of an example of how formal risk analysis is done, in the hope that others will make their own evaluations thoughtfully. Risk management is one of my hot buttons as an engineering and security professional, and I see way too many people applying "rules of thumb" they learned from their instructors or peers without really thinking about it.
For the record, I'd make that flight solo year-round, in one of the rental 182s I fly. I'd cross at 10,000 (reducing the window by a couple of minutes). I have a high degree of confidence in the maintenance performed by my rental organization, and the airplane has the G1000 with good engine monitoring capabilities, as well as that big moving map that will show the nearest land point. Taking oxygen might let me fly even higher, but there's a point where increased altitude reduces aircraft performance to the point where the window gets longer as you climb.
To reduce the impact I'd be sure to be IFR so I'd be in contact with ATC, I'd have a PLB, and I might also consider wearing a Mustang suit. I also have sufficient life insurance (with no GA exclusion) so that I don't worry about what my family would do without me, financially at least.
With my family on board, I would not make this flight except on a warm summer day where the water temps were as high as possible, and I'd add a raft to the on-board equipment.
This is the same decision I make when I decide whether to go over or around the lake on the way to OSH in summers. Generally if I'm solo I go over, if I'm with family I go around.
Best wishes,
