improving my very sad swim times

TI is good for focusing on your form and technique.
You have to then take the next step and give up a little form and distance per stroke to get speed. The books even mention this.
If you can keep your form solid, work on using more power. Just like on the run or bike, try to use your core to power through the stroke, while keeping your form.

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When I began learning how to swim last year I couldn't swim over 25m without being completely out of breath. I tried to power through my workouts but it got me nowhere, my largest gains in speed were after really focusing on form and swimming easier, not harder. My swimming was the equivelent of pushing a sheet of plywood through the water, so really working on my body position helped me. I did have access to masters (which was cheaper than paying for regular lap swimming to my surprise) and asked for a lot of stroke advice. Do you have any swimming friends who wouldn't mind looking at your stroke and body position? Or at least take video of you swimming? Video really helped me (and lots of watching good swimmers on youtube) figure out what I needed to change, I just had someone stand at the end and shoot and walk along side. Other than that, swim as much as you can! Be the first one there and last one out and you will find you will get more and more comfortable and get a better feel of the water. Good luck!

I was in the same boat as you last spring...I could run a 10 mile race, but after 50 yards in the pool, I'd be hyperventilating.  I knew how to not drown, but I had no idea how to swim.  I took a two private lessons from a TI coach to get started, and then I joined this tri group training class at my gym, which was led by a trainer who was a former college swimmer.  I got lucky b/c everyone in the class was most concerned with their swimming, so it basically turned into about 10 weeks of swimming lessons.  That got me prepared enough for sprint distance swims. 

Now that I can at least swim, this spring I'll be taking a TI weekend clinic.  I've read the posts too about TI being a method of slow swimming...but I think that is a matter of perspective.  I am not now and don't think I'll ever be a 1:20 swimmer.  I'd like to be consistantly under 2:30, and I'd be thrilled if I could even get into the vicinity of 2:00!  The thing is, that IS "slow swimming".  So, for people like us, TI could be really useful.

I know you said it's not an option, but Master's class has been so valuable to me.  There is no way I could have taught myself how to swim efficiently.  You tube and stuff like that helps, but you often times can't see what you're actually doing...so you most likely don't know what are your glaring flaws you need to correct.

For me, simply working on keeping my toes pointed has made a huge difference.  I don't have much ankle flexibility, but I was basically kicking with my toes pointed down...creating a ton of drag.  I had no idea until my coach kept telling me to point my toes then showed me video of it.