Joe,
I have just put a TREMENDOUS amount of time into researching this question and myself just (20 days ago) had a custom (wavefront) PRK procedure done on both eyes.
Let me preface to say that one thing that I became convinced of on researching this is that it is something that
you need to look into yourself and make an informed decision. I won't ever say, "It's great, you need to go for it." There are possible (very low statistical probability) bad outcomes that are not easily remedied.
So I'll try to break it down:
Procedures: Lasik vs PRK
Lasik and PRK are basicly the same procedure with one major exception, lasik involves a 3/4 circle flap being cut out of the surface of the eye into the central part of the cornea (the mostly outer part of the eye in front of the lense). In lasik this flap is then folded out of the way and an excimer laser used to reshape the cornea. Once done the flap is folded back into place and wala. PRK uses the same laser to reshape the cornea the same way BUT there is no flap cut, instead the surgeon numbs your eye and then uses an alcohol solution to soften the outer epithelium of the eye before scraping it off (think stiff rubber spatula thing to scrape). Once the outer layer is scraped off the laser is used to reshape the cornea and wala.
The biggest difference for you the patient between lasik and PRK is the recovery. Lasik is quick, have it done today, see good tomorrow or the next day with very little pain or discomfort. Wow factor is HUGE. PRK is not so quick. The doctor may tell you it's mildly uncomfortable for a couple of days but that is oftentimes an understatement. Remember, you have a deep brush burn on both eyeballs. If you go online and read some post PRK diaries you will find that for some it is fairly easy with a couple of days out of commision but for some it is 4-10 days of pain and very poor vision (I'll share my experience later). Some folks can't work or drive for a week, a few can't go back for two weeks. Some of this seems a little better in recent years due to better tech giving a smoother corneal surface that heals faster. As a general rule, PRK patients take about three weeks to be seeing as clearly as lasik patients on day one or two. Full recovery takes 3-12 months (mostly it's done in 3-6 months).
There are some (important) disadvantages of lasik. By cutting a flap you experience very little pain and you can see clearly almost at once. Patients love it and so do doctors, much less follow up and hand holding after the procedure.
The big BUT is this, the flap never fully heals. Never, the flap is there for the rest of your life. It will heal around the outer edge but the 95% in the middle never reattaches, it's held mostly by suction similar to contact lenses. Don't get me wrong, it is much more stable than a contact lense but I have read articles written by optometrists stating that 10 years post lasik they have been able to easily use a blunt instrument to dissect (lift) the flap of a lasik patient. There are also risks of getting infections under the flap, more so if there is exposure to contaminated water. Blows to the face, blasts of water, other unforeseen incidents have been known to dislodge the corneal flap, sometimes resulting in the loss of it. This is not a comprehensive rundown of the possible lasik complications but a highlight of the worst ones as related to us as boaters. PRK has none of these possibilities because there is no flap.
PRK has a longer recovery time, more pain and a higher risk of haze developing from scar tissue as the cornea heals. Most of the time the haze can be treated with topical steroid drops and resolved and the procedure has improved so that this is less of a factor than in the past. Also, PRK will have the best results if you avoid UV radiation as much as possible for a full year. My doctor told me to wear sunglasses for two weeks but the US Navy (which has done a LOT of research on this) recommends sunglasses all of the time outdoors for one month, as much as possible for three months and whenever you can for the rest of the year. Incidentally, the Navy allows lasik now and even performs it, but they have always preferred PRK.
So, as boaters how does this factor? PRK is generally reserved for folks who have corneas that are too thin to cut a flap and still maintain adequate thickness after the procedure. PRK is also (mostly) believed to yield superior results and be safer. Most importantly,
PRK is recommended for anyone engaged in CONTACT SPORTS. Your doctor will not fully appreciate what you are telling him/her when you say that you whitewater canoe, not at all, not even a little. Ours is as violent a sport as there is when it comes to eyes. Add to that contaminated water moving at high speed and sometimes under pressure and it gets even worse. There are a lot of boaters out there who have had lasik and it has worked well for them but there is more risk.
Also note that PRK is completely different from RK which was done by hand with cutting instruments. PRK is a laser driven procedure, the same as lasik just without a flap being cut.
My Experience
Please note that I am only 20 days into this adventure so it's still ongoing for me.
I don't tolerate contacts well, I can wear the most expensive (best) daily disposables for at most two consecutive days and even then they are better if I keep the time wearing them short. Contacts bother me the whole time I'm wearing them, my eyes are red and goopy at the end of the day and when I wake up the next, and if I try to grin and bear it, even worse things start to happen

.
I have a high pain tolerance and tend to take the more painful approach if I think it is better. I have elected not to cast several fractures. I believe that prolonged immobilization has negative side effects and the not casting would be a better, if
MUCH more painful, way to go. I am a chiropractor and I didn't miss a day of work last year adjusting people with my hands when I had three badly fractured metacarpals (hand bones). I also avoid doctors like the plague, not anything against them, I just don't avail myself to medical care unless I truly believe that it is necessary. I have not taken oral antibiotics in the last 16 years and had not used the services of a medical doctor for 13 years prior to my eye surgery so this is a HIGHLY out of character move for me.
I decided to look into having laser eye surgery done and did a lot of research. I went for a free consultation at a local practice and was assured that I was a good candidate (ideal even) for lasik and that I really didn't want PRK if I could have lasik. I was sent to a local optometrist for a presurgical workup and she assured me that I would be fine with lasik and that I didn't want PRK if I could have lasik. I was sent to the tech who did my presurgical scans (the surgeon is only in town for one day per month and practices the rest of the time in a large city) and he said that if I wanted PRK then that is what I should get done. The whole time I was insistent that I preferred to have PRK done. The day I arrived for surgery I found out that I was scheduled to have lasik. I said that I had been consistent in asking for PRK and was told that is should be fine but that I should speak to the surgeon. There were no objections from the surgeon and I had custom PRK done. It only took about 10 min from start to finish.
Day one I was in a lot of pain, had trouble seeing, especially up close, I was really photosensitive. Curl up in bed in a dark room with the blinds pulled and wearing sunglasses photosensitive. It was painful and very debilitating, I equate it to the flu, totally different symptoms but equally debilitating. I had lots of audiobooks and was mentally prepared so it was not a problem. Day two I could see better but up close still hurt and having my eyes open for more than a minute was painful. There was not much pain unless I kept my eyes open too long, which I did for unavoidable reasons. I also had a followup exam and was seeing 20/40 with a lot of trouble, very hard to focus to see the lines. Day three I was seeing better still, probably could have driven if I had needed to, and most of the discomfort was from the bandage contact lenses that are required for the first few days post PRK. Still couldn't work up close well and I rested my eyes a lot. Day four I drove (day and night) and had the bandage contacts removed, was seeing 20/30 (right eye) and 20/40 (left eye) and I was able to keep my eyes open. Eyes did feel irritated. Things were much better day five and by day six I was seeing very sharp and clear. My vision and comfort continued to improve and on day ten my vision was 20/10 (right eye) and 20/15 (left eye), better than I could ask for.
As I have said before, I am now on day 20 and I can see more easily now than I could a week ago. There are still times that my eyes are a little irritated or dry (dry eyes are super common, especially at first). I have some halos and starbursting around lights at night (again common) but that usually fades over the first year and it has never been so bad that I felt uncomfortable driving at night. Overall I feel that I see better now than I ever did with glasses or contacts and I have better depth perception and contrast in my vision.
I have been boating twice since I had it done. The two main risk factors for boating after PRK are UV light and infection. I went the first day with just sunglasses and then used my remaining antibiotic eye drops for two days as a preventative measure. I now have a tinted swim mask (it doesn't cover the nose) and aside from looking like a dweeb and enduring the mockery of my fellow boaters, it works fairly well. I'll likely stick with the mask for a few weeks and then go back to sunglasses.
I am very happy with how things have turned out so far and I really found that my PRK experience, wile painful, was not as bad as I expected.
If you (Joe) or anyone else has any questions I would be happy to add more here or on the phone, just ask.