As many people have suggested, a wireless network camera is liely your easiest option. If the WiFi signal is too weak at your boat, you could also possibly mount the camera somewhere closer to the "lodge", but if you're using motion sensing to trigger recording and alerts, it might be harder to eliminate false positives.
This is most certainly overkill for your needs, but there is free software for linux called ZoneMinder that you could run from a home pc, and it supposedly (I've never tried it) can connect over the internet to the camera and can do all kinds of fancy stuff if the software detects motion at the camera (ie., record video, send an email, sent a text , run a script on the computer,...). Definitely not plug-and-play, but once set-up supposedly works very well. It theoretically allows you to designate a small zone within the camera's field of view to watch for motion, and disregard motion appearing on the camera but outside this zone.