I’m looking to do an Olympic length trim so need to get to the point I can do 1500m non-stop front crawl. In open water.
You’ll need to get to the point where you can knock out 3000m non stop front crawl as after 1500m you need to jump on a bike for 40 km then run 10 km.
Anyway, took me a good 6 months to get from your starting point to feel confident of swimming 2.4 miles, and then I was still slow. add another 12 months on that to be happy to do that distance in a respectable time!