Ireland to Maine

Oh I can think of a few things better like seeing a whale breach beside you or have dolphin playing in your wake or looking up to see more stars than you've seen in your life, looking at your depth finder and seeing 900' below while zooming your radar out to it's max and seeing no other boat and realizing that God created this just for your eyes alone.

4 on and 4 off works fine for most under these less stressful conditions, but I stick with a 3 person rule because I want to have some bright minds when something really goes wrong. Generally speaking the watches are still done by two people, with the third doing a lot of napping and socializing to help the effort. My #3 is typically a mechanic for the big problems that might arise, and tasked with oversight and monitoring of all mechanical systems throughout. Sort of a dedicated watchdog and social fiend to help us stay sharp.

...and I don't know why, but I have a very strong desire to make this northern trip...

Well, it only takes me about a dozen of nautical miles from my home berth to have 900 feet or deep blue stuff under the keel - and not many more to have 900 METERS (or more!). Not to mention that sometimes Dolphins join us just outside the marina.
Anyway, I see your point, and each to their own, of course.
Imho, sailboats are a much more appropriate and also safer way to cross oceans, if I really should to.
But again, free will and all that!

I have had so many instances on these long trips where something broke and required 2 people to handle it. Either two people on deck trying to secure something that came loose and is doing damage to the vessel, or in the engine room, or etc. It would be very prudent to have at least 3 people on board on a crossing like this, if not 4. If you have a flooding situation, who is going to save you? You need one person minimum to try to mitigate the flooding if not 2 people, another on the helm, and a third possibly to get a ditch bag ready and to launch the life raft and load it. Is the wife strong enough to launch, secure, and load the life raft while the husband is dealing with flooding or fire, somewhere else in the vessel? Also in my vast experience, if something breaks that needs immediate attention, it's almost always in rough seas.

The number 1 skill of any Captain, is risk mitigation. The safety of the crew, the safety of the vessel, and the safety of the passengers.

Amazing how often on other boards, I read "Well, I did it alone" or "I know these people who did" but the problem is those who don't make it never post about it. Most of those who had major problems don't as they either lose the boat or sell it.

I know that any discussion about adequate crew in this scenario is pointless, but we're sharing opinions for our own entertainment. Here's mine:
1 I've run yachts from California to Hawaii, California to/from Alaska, California to/from Boston, operated in the Caribbean and Gulf of Mexico, and would not consider a trip such as the one proposed with less than 3 qualified watchstanders.
2 The third crewman on your voyage should be MacGyver.

That's my outlook and I appreciate yours may be different, but here's a story:
In 1998, a delivery Captain I know was running a yacht under 60' up from Cabo San Lucas to San Diego. About 300 miles south of destination, his sole other crew didn't come up for watch. The Captain went to shake up the relief, and found the man dead in his bunk. He was in his 40's and had no health issues that he shared with the Captain. The now solo operator of the yacht started calling "Mayday" on the VHF and after 20+ hours was heard by a friend of mine on a yacht headed south. That Captain, crew, and owner's party went to assist. There was nothing to be done for the deceased, so the rescue party attempted to contact the U.S. Coast Guard via single side band radio. No luck. Then the rescue crew issued a "Pan-Pan" over side band, which was heard by my wife in Acapulco on the yacht we were on. Ultimately, we contacted the U.S.C.G. via sat phone and put the rescue party together with them via side band radio. The result was that the C.G. would not assist in the situation as there was no threat to life or property at the time. The Captain on the assisting vessel, helped the by now very distressed Captain on the stricken vessel anchor and transfer fuel from barrels to complete the voyage after getting some sleep. The best advice for the solo operator then was to proceed to San Diego, as checking into Mexico with a dead man would result in the most difficult bureaucratic issues.

Otherwise, The National Institute of Health has published the results of a STUDY, that concludes:
CONCLUSIONS:
Since chronic restriction of sleep to 6 h or less per night produced cognitive performance deficits equivalent to up to 2 nights of total sleep deprivation, it appears that even relatively moderate sleep restriction can seriously impair waking neurobehavioral functions in healthy adults. Sleepiness ratings suggest that subjects were largely unaware of these increasing cognitive deficits, which may explain why the impact of chronic sleep restriction on waking cognitive functions is often assumed to be benign. Physiological sleep responses to chronic restriction did not mirror waking neurobehavioral responses, but cumulative wakefulness in excess of a 15.84 h predicted performance lapses across all four experimental conditions. This suggests that sleep debt is perhaps best understood as resulting in additional wakefulness that has a neurobiological "cost" which accumulates over time.
Safe travels!

Yes, to the people who say they only get 4 hours of sleep per night, I'd just suggest seeing a sleep doctor. You don't realize the impact because that's your norm. I've known people like that who then got CPAP and the first night they slept 8 hours, they were amazed at how much better they felt.

Well I don't have much experience, only about 70 runs up and down the east coast, 30 years of professional running and 63 years on boats. But I've had a few breakdowns and a few fairly dangerous situations like having a bilge pump hose break turning it into an inlet in 8' seas. Yet I've evidently (since I'm still here) never hit a situation I couldn't handle. It's always best to do things the safest way possible in keeping with your circumstances. It would be safest if we only ran along with a Coast Guard cutter nearby, but not practical. Couples and solos cruise all over the world every day, loving the experience and surviving quite well. I met one guy who rowed across the ocean alone in an 8' boat. The fact is that it doesn't much matter where you are. Big waters don't kill people. It's the first 6' from where your toes touch water that does it.

[QUOTE="olderboater, post: 290964, member: 40728]Most of those who had major problems don't as they either lose the boat or sell it.[/QUOTE]

I don’t buy most, maybe some or a few. Humans have proven incredibly resilient in emergencies over the centuries.

a lot of very good advice in this post ...

On the recent return from Newfoundland to Panama, I had a crew of four on board. Good thing to do.
When we arrived at Colon for entry to the CZ - a requirement is multiple rope handlers - which I didn't have to pay extra for.