diff --git a/apps/suw/README.md b/apps/suw/README.md
index 977e102ee..0dcad0937 100644
--- a/apps/suw/README.md
+++ b/apps/suw/README.md
@@ -4,16 +4,22 @@ A watch that does just what I want when I am at the seaside.
 
 Very much a work in progress. Requires location to have already been set in mylocation.json using MyLocation app.
 
+DO NOT RELY ON THESE TIDE TIMES! This is in development.
+
+When working, you will set the next tide time (high or low) in application settings, the watch will then calculate approximate next tide time by adding 6 hours and 12 minutes to the tide time and keep doing so until reset.
+
+This may become very unreliable over time and will need periodic realignment.
+
 ## Many faults
 
 - [x] app icon invisible 
 - [ ] no need to check sunrise and sunset times so often
-- [ ] default location data doesn't show up in the simulator for some reason
-- [ ] I don't understand how to use the IDE with multiple files
+- [x] default location data doesn't show up in the simulator for some reason
 
 
 ## Many of the to-dos
 
 - [x] add sun image to main screen
-- [ ] show alternative data on tap 
-- [ ] show tide times for given location
+- [x] show alternative data on tap 
+- [x] show tide times 
+- [ ] write tide data back to json file when flipped to keep it up to date when app reloaded