Name: TidalFlow
Rating: 4.2 (180 reviews)
Author: HermoT

A simple visualization of the current day's tides with respect to dawn, sunrise, daylight, sunset, dusk and night times. TidalFlow serves as a great aid when planning activities in and around the water.

IMPORTANT: Free to use, but please read the Fair Usage Policy FIRST: http://bit.ly/tidalflow-fairusage

User Guide: http://bit.ly/tidalflow-userguide

TidalFlow can be configured in 2 ways:
1) In the widget itself, you can press the start button to bring up a menu. 
2) Use either the Garmin Connect app or the Connect IQ app to configure the settings for TidalFlow

When using the menu inside TidalFlow (option 1), you can set the location by either letting the device detect your position, or entering the coordinates yourself.
When using the Connect or Connect IQ apps (option 2), you can manually enter the coordinates and then save them to your device.

TidalFlow makes use of a paid web service, but through generous donations received from users, I offer this great service for free. However, please note that TidalFlow restricts updates to 3 updates per day. Be mindful of this when you change settings, as with each change it will attempt to refresh the data. After the 3rd update, your device will be throttled until the next day.
I will soon add a link to the Fair Usage Policy that explains the restrictions around the usage of TidalFlow.