GPS data from swim

I mentioned a few weeks ago that I got a new to me GPS system to track swims.  I'll do a full review of it in the future, when I've used it a bit more, but here's the data from this week's swim and a little about why it is interesting. (really, when is data not interesting?)

First, the GPS provides a map of the swim, with a heat map for pace.

The swim was a simple out-and-back to the third staircase. I was just shy of 800m with 16 "laps" of 50m each (the last one was 47m).

I like seeing how straight my swim was, and where I turned around (a bit past the third stairs). I would like to be able to zoom in a bit more. Which the ap doesn't seem to have the ability to do.

Now the more interesting stats:

That's my pace (in yellow) and my stroke rate (in pink).  Even if you can't read the numbers, you can draw a few conclusions about my swim.  The biggest one is current.  Knowing I turned around half way through (out and back swim) you can see what the current did to my pace. Sloooooowed it down!!  And, to compensate, about 100 m later, I picked up my stroke rate.  I must have realized I was going slower, or just wanted to finish.

I find the very high stroke rate for the first 100 m also very interesting.  That must be a response to the cold and wanting to just MOVE to warm up.  I don't think I realized it was that dramatic. I will want to see if that data is repeated in future swims.

I was having such a good time out there, that my 32 min earned me the "last swimmer" out there award this week.  Here's a shot a friend got before I got out.

Viadoom Swim/Walk

Usually I swim with the Notorious Alki Swimmers for my weekend swim.  As the name implies, we swim at Alki beach. Seattle is now, in the midst of "Viadoom" while, for three weeks, the Alaska Way Viaduct is closed and the replacement tunnel is not yet open.  I'll skip the politics of this in this forum, but suffice it to say, the impact on traffic, city wide, is anticipated to be significant.

I usually take the viaduct to Alki (or home) and so planned to meet up with a few north-end swimmers at Golden Gardens instead.  Three of us showed up on a beautiful, sunny, flat day.  The water was clear, and the sun was out. I almost worried about sunburn!

Golden Gardens is known for having a bit of a current as you swim around the point. I'd done it many times before and, although I'd felt the current, it had never been an issue.  Until this time.

I also have a new toy (I'll post on that soon) that is a GPS and gives me real-time auditory feedback on my pace. This ended up being very helpful, and a great safety tool, in this situation.

As I got used to the temperature, and started getting into my pace, the GPS was telling me that my "laps", which I'd set to 50 meters, were about 1:09 to 1:25.  I knew this was fast for me, but since I usually swim in a yards pool, it was hard to track how fast.  The swim was easy. I was watching the beautiful sand and sea floor. I had a goal of about a  mile, but after 650, the other two swimmers were coming back, so I turned around with them.

The next lap jumped from 1:20 to 2:20 then to 4:20. I wasn't sure, since the GPS is new to me, if this was a sign of the current, or of the GPS malfunctioning. You can see the change in pace around lap 11 here:

Either way, I decided that it was safer to start swimming towards shore, so I'd be closer in if I needed to bail.  This was a good idea.  It took me minutes to get near shore. And then, the current was pushing me so hard that my slowest 50 m was over 5 min! I got close it to shore and started to walk, in shoulder deep water, to see if I could get free from the current.  I couldn't.  But I tried for a few min.  I realized I was making no progress, so I got out, and walked back to my gear. My friends met me half way back with my shoes and towel. You can see my route here:

Notice that the color of the line is an indication of pace.  The green is faster than the blue. The darker the blue, the slower I was going.  Basically, from the turn around spot, I dramatically slowed down.

What did I learn from all this?  

First, swimming with friends is a good idea, I knew they were watching out for me and aware of where I was.  

Second, the GPS ended up being a real safety device. I wasn't sure I'd like the every 50 m updates, but in this case, it highlighted for me much quicker than I would have noticed alone, that my pace had dropped dramatically. 

Third, the habit of swimming parallel to shore is a smart one. I knew if I couldn't break the current, I would be able to turn around and swim across and with it to shore. Another safe choice.

Finally, once again, I got into an uncomfortable situation and got myself out of it safely.  As I push my limits swimming, I need to also balance that with swimming safely. This was a good test of my response intuition and I'm proud of how I responded. I never felt unsafe. I was confident the whole time that I knew what to do.  That was a good learning experience.

And really finally, there is no shame in walking.  I don't regret it. And I still think of this as a fabulous swim. Every swim teaches me something new.  This one was about current, and planning.