Distance/OW workouts

I have three OW swims in late May/early June. Two are long distance (2.4 and 3.1 miles). I have been doing one day a week of distance work as prep. I have some difficulty in creating a good distance workout for myself that isn't boring (4 X 1000 isn't very fun). Given I have time for about 4500-5000 in our practice time, I was wondering if anyone has any good distance workouts to suggest? You can always PM me with your ideas if that suits you better. I realize there is an OW section on the forum but figure more people view this section.