Like Michael said, there are high tides and low tides twice a day, so it wouldn't be a problem for the tide to be going out in the morning. For example, I just checked today's tide table for Nassau in the Bahamas and low tide was about 6:29 this morning, so if they landed 5:00 am, the tide would've still been on its way out. And if you need it to be a different time for high or low tide, just pick a different time of year.
[added] Apparently in Nassau (which I chose at random), the time of high tide changes by about 1 hour 10 minutes a day, because this Wednesday the high tides will occur at 3:21am and 3:47pm. So if you want Lois to land the boat just after sunrise (because she saw the sun peak out), let her land it right after high tide, and pull it farther up on shore before the next high tide hits early that evening.
