This may or may not be an option, but I agree-it's really hard to truly relax when you're constantly running after the kids. I view the vacations during the early years as great opportunities to expose your kids to something new and get some great photos! This year we are DELIGHTED because we're taking our nanny with us. Of course we still want to spend most of our time with our kids, but for one (or two) half days, I want to park my butt on the beach with a book and no one else! My husband and I also desperately need some time to ourselves, so this will allow us to go out in the evenings on our own. Many families do this -if they don't use a nanny regularly, they hire a college girl to come along and watch the kids sometime. They can usually be found fairly cheaply because if you're headed to the beach, then they still get tons of time off and a free beach vacation!
Another thing you see a lot are grandparents or grandmas on vacation with their kids and grandkids. This isn't only to give grandma a vacation! Before my mom died, we would go on vacation with them and they would watch the kids a night or two and for a morning or something.
If it's too late this year, think of some of those options for next year. We probably won't have a regular nanny next year, but I'm still going to go on Sittercity or care.com and get a college kid home for summer who wants to make several hundred bucks and get a tan!
You and your husband can also trade off if no one will go with you. Give him a half day one day and yourself a half day the next. If you're going to a resort, MANY have certified, licensed babysitters you can hire for an evening.