Hi there,
I saw your post late last night but I could not reply.
In short, I would say - GO FOR IT!!!
A longer answer: I used to swim on a regular basis, 1x a week for 45 minutes, long time ago. The stupid hours the pool facility kept for lane swim forced me to get up at 5:25 am so that I was hitting the pool exactly at 6:00am - when they unlocked the doors from the change rooms to the pool. That was summer or winter. I guess I loved it enough to climb out of warm bed on pitch black winter mornings. At that time, i was not trying to lose weight, it was just something I enjoyed doing. I actually got nicely defined arms from the swimming, even though I swim only breast stroke (and I swim a somewhat different breast stroke - I don't go under water like it's customary here - I grew up in Europe and that's the way I was taught to swim. I also felt that swimming did a lot of good for my abdominal area.
Then I stopped (life happens). Of course, I gained weight (not only because I stopped swimming, there was a number of other reasons - depression, being horribly unhappy with myself, you know the reasons - we have all been there.
).
I resumed swimming last year again - I am happy that now the pool has better hours and I can sneak out for an extended lunch break and get a 35 minute swim in during the day (2x a week).
It is a good workout for the entire body. And do you know what, I just read in the last issue of Oxygen that breast stroke burns a whopping 590 calories per hour (only the butterfly burns more, all other styles burn less).
The magazine also included info re how many laps/lengths you need to swim to cover 1 mile so I started to count (I never counted before). Counting pushes me to go faster (i am a slow swimmer).
So if you enjoy swimming, SWIM!!!
Personally, I love weight lifting so I don't understand how somebody can not enjoy it but I DO understand that we are all wired differently. :-)