I have already established that I'll easily swim the entire distance of the Alcatraz swim. I can already finish 2500 meters in about 45 minutes and had no problems doing so. Of course there will be a difference when I have to swim in a strong current and in freezing water, but I still believe that this will be doable. This is why I have shifted my focus towards speed.
I know I can swim 100 meters in less than 1:30. But I still struggle with keeping a pace like that for any longer. The last couple of times my struggles have been to keep every interval below 1:40, but with more practice I'm sure I'll be able to turn up the overall speed.
As usual my watch isn't perfect when registering my laps, but that doesn't matter her. After 300m of calm swimming (stopping after 200m to massage my foot to prevent cramps) I started the intervals. My first interval time ends up being less than 1:30, but already on the second interval decline in speed is noticeable. The 20 second breaks doesn't seem to be enough right now, as I gradually loose speed the further I get into the session.
I believe in having a goal that isn't easy to complete, and will therefore continue to work towards a sub 1:30 time overall. But on the way I will try to push myself a little bit at the time. My next small goal is to do every interval at 1:35 with 25 seconds break every time, reducing the break to 20 the time after and so on. Hopefully I'll get to my goal in a month or two!