You must give priority to flying the helicopter while dividing your attention between navigation and planning. When determining an altitude to use while diverting, you should consider cloud heights, winds, terrain, and radio reception.
LOST PROCEDURES
Getting lost in an aircraft is a potentially dangerous situation especially when low on fuel. Helicopters have an advantage over airplanes, as they can land almost anywhere before they run out of fuel.
If you are lost, there are some good common sense procedures to follow. If you are nowhere near or cannot see a town or city, the first thing you should do is climb. An increase in altitude increases radio and navigation reception range, and also increases radar coverage. If you are flying near a town or city, you may be able to read the name of the town on a water tower or even land to ask directions.
If your helicopter has a navigational radio, such as a VOR or ADF receiver, you can possibly determine your position by plotting your azimuth from two or more navigational facilities. If GPS is installed, or you have a portable aviation GPS on board, you can use it to determine your position and the location of the nearest airport.
Communicate with any available facility using frequencies shown on the sectional chart. If you are able to communicate with a controller, you may be offered radar vectors. Other facilities may offer direction finding (DF) assistance. To use this procedure, the controller will request you to hold down your transmit button for a few seconds and then release it. The controller may ask you to change directions a few times and repeat the transmit procedure. This gives the controller enough information to plot your position and then give you vectors to a suitable landing sight. If your situation becomes threatening, you can transmit your problems on the emergency frequency 121.5 MHZ and set your transponder to 7700. Most facilities, and even airliners, monitor the emergency frequency.