Half Marathon info

I am looking into entering a half marathon and training information for it. The problem is that I can't really run because of arthritis in my knee. My doctor would not be happy. I can walk about 4 mi per hour and that is my limit, except for short distances. I am wondering if people walk the half marathons too and how long it would take to complete one. Any help is appreciated.

I know there are some half marathons that people walk. If you walked at 4 mph, thats 15 minute miles, so that'd put you at 196.5 minutes, 3.3hrs. You will want to look for one that says walking though because a lot of marathon courses become closed after a certain time frame. So, for example, they'll have people close up the course if you fall behind a 16 minute mile pace and anyone back that far would get picked up and driven to the start/finish. 16 is just a number I pulled out though, not sure what they usually are but it will likely indicate on the race site and you can determine if you could beat their pace or not.

the half marathon I did had walkers and runners (more of the runners). The last walker finished around 5 hours I think. Since a marathon was being run as well, the course was open for 7 hours.

It takes me 1.5 hours to walk/run 10k. So I can Imagine at least around 3.5 to 4 hours for Half marathon. Do not forget, marathons are not races. They are meant to raise money for causes and to surpass yourself!!! I'm training for one now and all I want, is to do it!!! No matter what!!! Go for it girl!!!

Thanks for the replies! I am looking at a few that are done at the same time as marathons, so it sounds like that might work. I really want to do this.