1. We'll need to buy a used boat (we've always know this; new boats are extremely expensive, often sporting price tags much higher than the cost of our house).
2. We'll need to do a lot of our own work on the boat. We might not be able to make every fix or improvement ourselves, but we should be willing to put in the elbow grease whenever possible. We should be ready to learn.
3. We'll need to alternate between working and sailing so that we can generate income. Right now, a six-months-on, six-months off schedule looks like it might be doable. We'd top up the cruising kitty, then head out again for a set period of time, then return to earn some cash, etc.
4. We need a realistic sailing plan. Forget heading off to Tahiti. Who knows? That might happen, but such a trip takes funding and skill we don't yet have. However, a trip down the Intercoastal Waterway, followed by a few months in the Florida Keys, later followed, perhaps, by time in the Bahamas and then the Caribbean - that's doable. Baby steps.
5. Unless the housing market improves significantly in the next few years, we'll probably rent out our house. That would allow us to maintain some landlubber security without the burden of a monthly mortgage payment.
Henry David Thoreau famously said, "If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them." It might take us a while to build that foundation, piece by piece, but I'm convinced we can do it if we maintain focus over the long term and channel our resources appropriately.