Chapter 3: Getting Started 25Cancelling an MOB WarningTo cancel an MOB warning, press and hold the DEPTH and SPEEDkeys for one second. The MOB information is cleared and the displayreverts to the Waypoint/Bearing/Distance page.The MOB warning will also be cancelled if an appropriate message isreceived from another instrument via the SeaTalk connection.3.9 Key FunctionsThe five keys have the following main functions:• NAV (POWER) is used to:- Turn the RayData on and off- Access the Nav Chapter of display pages, if the RayData isreceiving navigation data via the SeaTalk and/or NMEAconnection• DEPTH (LIGHTS) is used to:- Access the Depth Chapter of display pages, which include depthand temperature displays and alarm controls- Control the lighting and contrast level for the screen, and thelighting level for the keys• SPEED is used to:- Access the Speed Chapter of display pages, which include speedand log displays- In combination with DEPTH, send/cancel an MOB warning• ÚÚÚÚÚ and ÙÙÙÙÙ are used as follows:- ÙÙÙÙÙ to move forwards through the available sub-pages, increase avalue, or move forwards through setup options- ÚÚÚÚÚ to move backwards through the available sub-pages, decreasea value, or scroll backwards through setup options- ÚÚÚÚÚ and ÙÙÙÙÙ together to perform operations such as lock/unlock theheading, reset a value or make a selectionThe key functions, including the combination key-press functions, aredetailed in the table in Appendix A.