...you have a well-thought-out plan. Many first-timers don't, nor do they listen to advice from people who have been in their shoes if it runs counter to their mindset.
... the upside is there's really no such thing as a solo hike on Whitney in summer due to the crowds. The downside is that you have to mentally and emotionally be prepared to mostly do it on your own... ... so you really need to focus on beating the potential of AMS... ...don't psych yourself out before you begin (it happens).
Acclimation is the best deterrent to altitude sickness... ...The problem for a dayhiker is that 4500 feet are waiting for you...
I had myself (erroneously) convinced that I was one of the lucky few to have no predisposition to AMS... - it's unpredictable. Sherpas in the Himalaya who've been running up and down 8000-meter peaks their entire lives have been known to die of altitude-induced edema at 6000 meters or so.
Anyway, trust me when I tell you that making my way down from 13,500 feet on Whitney with raging AMS, by myself, was the hardest thing I've ever had to will myself to do. Worst headache ever, incessant nausea, kaliedoscope dizziness, DT-shakiness - but the worst symptom to overcome was the most incredibly lethargic feeling. I just wanted to lay down and go to sleep - screw everything else. Of course, I'm a guy, so I lied every time someone would ask me if I was OK or needed assistance. Gotta perpetuate the rugged, independent male stereotype, right? Actually, I just couldn't believe I had AMS and was mentally trying to write it off to food poisoning or some other malady outside my control.
...proper acclimation became Job One every trip to altitude after that. I never, ever want to feel that way again...
Nope, you guys aren't confusing me! I recognize everyone has slightly different experience/advice, but that's a good thing.
Bulldog (and everybody), thank you for your honest detailed account of AMS and all experiences. I REALLY need to hear this kind of thing, and for a less experienced person it does not "go without saying"

. It does do 2 things:
(1) knowing ahead of time what to expect (how it feels, what it makes you think-feel-do) enables me to stay calm/collected and better handle the situation.
(2) re-focuses me on strategies for better mitigating risks like AMS, focus on what is important. I need to be VIGILANT about acclimation, hydration, pace, even nutrition.
Before you guys told me all this, I would have NEVER asked a non-partner on the trail for assistance or company unless I was in dire straits. Now if I need to head back down on my own, I will say hello and ask them if I can hike down with them because I'm having (x) problem or want some company. I still might not ask them if they look like they're hiking at high speed, but I'd eventually ask somebody who is at a pace I can maintain.
The other thing that is a big help is to not psych myself out! I tend to get anxious beforehand for major unexperienced events, so I reach out to people like you all, get advice, take advice, prepare, then when I actually execute I'm as prepared as I personally can be and have fun instead of being worried. I think it's really important to be able to get advice from people to change my mindset; I'd much rather do that than learn the hard way by proving myself both wrong and stubborn.
So this is where I am right now:
- train to my plan
- consider substituting White Mountain, especially if I do not get my 7/14 Vivian-Gorgonio permit or just substitute it for overly popular HumberPark-SJPeak
- reconsider my acclimation plan (stay at Horseshoe meadow instead of tagging along with Original Partner doing photography at lower elevations)
- discuss/get Diamox from doc, 62.5 mg to 125 mg twice/day 2 days prior
- come up with vigilant concrete plan for hydration, pace, nutrition, ectrolyte pills
- prepare my pack as if solo hiking (e.g., 10 essentials, map mountain water sources, don't overpack)
- prepare my mind as if solo hiking
- ask to tag along with other hikers on trail if left alone by my group
- FOCUS...Forget Others Concentrate Upon Self
- Be a tortoise, not a hare (don't have to keep up with the marathon men, and going slower will actually HELP me with AMS)
- recognize and deal with AMS
- deal with group dynamics ahead of time
- discuss/plan on-trail communication and etiquette ahead of time (e.g., I have a tendency to run ahead when I get excited, need to learn to not do that; leave pack on trail if off-trail, etc.)
- keep looking online for permit availability for NP (I have a New Partner, Old Partner is good with him going, NP enthusiastically committed to all training hikes and "got your back" philosophy, is willing to take the chance of getting day-before walk-in permit)
..... Humbly asking you guys for suggestions on one more topic: nutrition.
REI Whitney Guy suggested I use Hammer Perpetuem for on-trail nutrion. I have used Hammer products before for trail running, I like them, they're better quality. What do you think of that? I prefer whole unprocessed foods, but I want to keep the nutrition simple. What do you all use for nutrition?