Why am I swimming slower?!...

I'm right there with you!  Ok, actually a good bit behind you, but in principal...whatever.

I was closing in on 2:00/100 for my 10-20 lap base intervals (around :52 for single laps with short breaks), and the last month or two my speed has decreased.  I don't know what it is either, but lately I've been doing 2:20/100 at the same perceived effort.  If I up my effort to, I can get down 2:16/100, but it's a big increase in effort for a very little return.  That 3K wetsuit splash took me 1:20:00.  Ridiculous...I don't like it but like you said...IM is just a few days away and I'll make the cutoff so I'm not going to worry about it.  But dang...I'll be visiting a swim coach this winter.

Thanks for the replies, guys...I understand that long continuous swims are not ideal if that's all you're doing, but I've seen a lot of back-and-forth of the benefit of including one long swim per week. I follow a plan by Matt Fitzgerald and he has me doing intervals 2x per week and a long swim once a week. His plans have worked well for me with  my OLY and HIM races so I'm going with who I trust...It's really weird, but again, I'm not going to try to change anything. I feel like I'm a strong swimmer and I suppose that's all that matters...feeling good in the water. (even at a slow pace)

I do have another question, though...My last swim workout (minus the practice swim on Saturday) does call for some speed work. It's only a 1200m swim, but for the person who mentioned not pushing it too hard would you advise against this??

It's funny...I kept hearing about everybody getting so nervous and having all this doubt before this race while I wasn't and I would think to myself, "what did I do so right that is preventing me from worrying at all?". And then out of no where, on Sunday all the nerves came crashing in. LOL!!

I'm supposed to embrace this time, right? 

Other people may advise differently, but as I understand a taper, your intensity should not change, just your volume.  You want to maintain the cues to your body that "yeah, we're going to be working hard soon", but you don't want to do so much of it that you add additional fatigue on top of what you are tapering from.

Trust your training!  Don't worry about the 1:20 goal, there are too many factors that can come into play - it will happen or it won't.  Just swim the way you know you can swim and enjoy it!

As for the 1200, what exactly is it?  Something that short shouldn't be anything to worry about (assuming it's not a 1200 TT).  

Here's the workout...The first time in as long as I can remember that the drive time is going to take longer than the workout.

WU: 350 @ low aerobic intensity
MS: 3 x 100 @ VO2max intensity, RI=1:00
4 x 50 @ speed intensity, RI=0:20
CD: 350 @ low aerobic intensity

That won't hurt you.

and don't wear those booties you mention in your log!