Finding pools for endurance training (UK)

Hi all!

UK based - I need to do some endurance swim training, and I've found a few open water spots I can drive to and am able to fit around work during lighter hours (work 9-5:30pm) but I'm having trouble finding local pools that offer sessions to cater to this, they typically tend to be something like:

• Lane Swim medium/fast
• Family Swim

And only ever for an hour each. Google is coming up empty apart from showing me the same leisure centers regardless of what I type. Should I look at private pool hire? As this needs to be regular I am trying to avoid a massive expense. In the spring/summer months it won't be so much of a problem as I can use the river, but darker hours/season will be a problem.

Thank you in advance :)