A little background: I got on the topic of security with the yard manager where I go for Winter storage, and he suggests owners leave their boats unlocked (and remove high value items that aren't attached to the boat) based on the logic that in most cases the value of things which might be stolen are less than the cost to repair break-in damage.
The marina has Wi-Fi so I was thinking it would be worth it to put a DropCam into the boat, positioned to record the face of anyone who might open the companionway and enter and trigger an alert based on a motion event. The DropCam is a great product, but its Wi-Fi reception is dismal and doesn't have enough range. I tried it and it's a no-go.
So I started looking at alternates and found an iOS app called Manything that will do what I want, using an iPhone or iPod Touch (which you can find on eBay if you don't have an extra to spare). You can add LED lighting for night vision, and power it all from the boat's solar panels/house bank. You could use it on a phone with a data plan, but that could get expensive if you use it full-time. (The Manything app does include settings to limit the amount of data transmitted by bandwidth; by total data/month, by video quality and FPS, and has extra settings to allow/disallow using cellular data -- or use it with lower frame rates.) There's more to it, but it looks like it has potential.
It could also be used to watch your dog when you leave the boat, a child monitor or other home/office surveillance. This is an FYI to those who might have an interest. I'm not endorsing it, just testing it, but think it's probably of interest to others. My initial impression is that it's pretty cool.