Swim Training as Open Water Swimming
A little background. I have just moved to an area that gives me access to a 110 acre Lake. There is a small beach 1.2 miles from my house. This morning was my first swim in the lake where I promtly met 2 other triathletes in the middle of the lake. There is very little admin time associated with me swimming int he lake. I also have two rec centers near me. However, the closer rec center is currentlye very croweded with summer camps. The further one (about 15 minutes one way 
) has a pool for lap swim only all day so access to a lane is more guaranteed, but again its a least 30 minutes of admin time round trip plus changing time. Cost of the rec centers are about $200 for a 6 month pass.
Questions:
1. Can I open water swim my way to IMFL? Assuming lake temp is reasonable through about Oct 1 and then switch back to the pool..
2. Do I need to add at least 1 Pool session a week to do interval speed work??
3. Any suggestions on putting some routine together for OWS sessions...??
4. I have a Garmin 205 which from the user manual doesn't recommend being soaked for long periods of time. How do I track distance? Do I really need to or should I just use the clock for duration??
5. SAFETY...should I be strapping a flotation device to myself? I'm thinking one of those baywatch flotation devises on a rope attached to my waste or something. I'm thinking of low tech safety device for in case I get a cramp or something. Today's swim was without a wetsuit as the water was pretty warm.
I feel very lucky to have access to this lake, but this seems way different than doing any sort of Pool session and I'm not sure if this is a good thing or a bad thing.
I would say I'm a pretty average swimmer, when up to good swim fitness I'm about a 1:42 T pace for 1000 yards, Swam a 1:09 at IMLP last year.
Comments
Otherwise, I wouldn't personally worry to much about specific intervals-that can easily be simulated outside. For example, if the workout calls for some fast 100s, you know you have X amount of pick ups while out there swimming.
Here are my thoughts:
The safety question depends on how confident you are about your swimming. If you were on swim teams in your youth, have been swimming all your life, etc, you'd probably find a "low-tech safety device" frustrating and inhibiting. If you are nervous, though, why not swim circumferentially, close to shore, rather than across the middle?
As to distance - go to google maps, or mapmytri, and get the distance across the lake as a rough aproximation. I swim regularly in a small lake, and know that it is about 600- 635 meters across (depending on time of year and how much the water level has dropped). I count strokes whenever/wherever I swim, and know that I do about 88-90 strokes/100 meters in open water, so I use that as my means of determining how long an "interval" is if I wish to do some. It's a pain to keep looking at my wrist and trying to see my time, so I just don't do that. Remember, without turns, your stroke rate/distance will be higher in open water.
Routine? I don't think you need to follow the written EN swim plan precisely. Just decide if the day is going to be long slow distance, or tempo (4-6 x 7-10 minute "intervals") or something like that. At the end of each swim in the lake, you can finish up by throwing down 6-10 hard "intervals" of 30-60 strokes, which is probably all you need to keep the motor fine tuned.
Training should be about fun. I can't see how it's *more* fun to go the pool route when you can swim outside any time you want.
Lastly, what about power boats/jet skis? That's what I'd worry about most; my little lake doesn't have any.
One more thought: You might consider buying this or even this from DeSoto. I regularly swim with the Speedtube in the pool, and have used the bibjohn in warmer water outside (up to 80F). This would solve your safety concerns ( a wet suit IS a flotation device), and would also make your swims more race-day like.
Don't forget, EN has a 25% discount from DeSoto.
I did 95% of my trainining for IMAZ in open water. I can't stand swimming in the pool, so if you would be more apt to go in the open water then I say by all means go for it.
Al, thanks for the speed tube Idea, I think this might work well for my situation. Even in warmer waters at least half my body would be exposed but the other half pretty bouyant. I have yet to see a boat on the lake since I've been there. the boats that are tied up on in the docks look like slow movers and no signs of jet skis. workout ideas are great, long slower (basically IM race pace for me) or sets of 7-10 minutes of harder effort.
Lauren, agree and a lot of my figuring out safety while OWS is for my wife's benefit and frankly I want them to find my body if I should have a heart attack while swimming. There are also group swims that people meet up for. Tagging along should be easy.
At my experience level after about 10 times of Swimming in this lake I will have doubled my OWS experience...
Nate, I'm not much of a swimmer but am very comfortable in the water. Only learned to freestyle a a few years ago for my first tri. Now I prefer OWS to a pool by a long shot. That is if it is reasonably clean and I can't see the bottom. For some reason if I can see bottom I start to tense up.... go figure.
All my OWS are alone. Carole doesn't like it much but she isnt interested in following me in a boat. Mostly I dont mind boats around but a few times there were some jetskis.... people who ride them around here are reckless, and scary.
The attached screenshot of my last OWS in Brewer Lake, water temp @ 68*, 58 minutes and about 1.7 miles
Btw, if you are going to do a lot of OWS then you can probably justify a Garmin 910xt. It is not perfect, accuracy-wise, but if you are a classic EN data junkie then just suck it up and buy it!
I also mapped out what I thought was my swim route and I can see another advantage to OWS being adding volume a lot quicker. Meaning in about 30 minutes of OWS I went as far as a 40 minute swim in a pool. Less stopping time....
Solo swimmers are hard for boaters to see, whether it is scullers or motor boats. I have an inflatable dive buoy on an ankle tether (like a surf board). It is bright orange. Easy to spot. Boaters can spot me from a distance and usually are polite enough to give me space. Another swimmer has an inflatable beach ball on an ankle tether. The big group of swimmers is easy to spot.
Like Al, until I had a 910, I counted strokes. I counted in the pool, then transferred to the lake and added a few more to make up for pushing off the wall. The 910 is not perfect. I swim VERY straight. The 910, on download, has more zig zag and even back tracking than I am actually doing. But for overall accuracy, it is good enough. Plus I prefer OWS to the pool.
You can gain confidence with practice.
so I've had some ups and downs all good experiences to get under my belt, Not sure if if I'm getting more fit but confidence in OW is going up. One episide of some crazy gusty winds which taught me a solid lesson of how much harder it is to swim when there are little waves and the wind is blowing. And last Friday when in the afternoon the water was in the 80s with pockets which had to be in the 90s...I pulled the plug and basically dog paddled back to shore afraid of overheating. All solid lessons on OWS. The huge benefit so far happend this past weekend. After my long bike my family decided to go to the beach. I was able to "sneak" in a 15 minute session with no problem. Focused on form and swimming smooth, but ultimately this was 15 minutes of opportunity that I would otherwise not have.
Big news (well, not that big) was as I stated in a prior post, I order a safer swimmer. Its a fancier version of what Michele is describing.
http://www.ishof.org/safety/ssd.htm This thing is really nice. It works as advertised. Basically a bright orange bag that straps to your waist, you can put your keys and clothes inside and then blow up an air bladder. Allows people to see you very easily and also you can wrap your arms around the thing to float while adjusting goggles or just taking a break. big confidence builder and its around $40.00. I'm only casually aware that it is there while swimming..