SCAN navigational device

Skilled sailors can find their latitude with relatively-simple navigational equipment, and a basic spell will point the way north with decent accuracy. However, until fairly recently it was considered impossible to know one's position east-to-west with any degree of accuracy while at sea. Doing so requires knowing not only the precise time of day onboard the ship, but also simultaneously knowing the precise time of day at a fixed location, such as the ship's home port.

Modern artifice has developed sealed chronometers that can function with high degrees of accuracy aboard ship; however, they remain prohibitively expensive, large and unwieldy, or both, and have yet to catch on. Instead, most ships employ a SCAN (Solar-powered Communication Aid to Navigation), a simple but ingenious application of the sending spell. Companies that manufacture SCANs keep buildings with high-precision clockwork and staffed at all hours; on board ship, the SCAN is activated at local noon to send a message back to this home port, which supplies the current time at its known location. A quick bit of mathematics on the part of the navigator is sufficient to determine the ship's current longitude.

In order for them to be constructed more cheaply, most SCANs are designed to function only at local noon, and are only able to send to their home port. A variety of artificer conglomerates make their own models, so details vary; some are able to communicate directly with a clockwork construct, negating the need for staffing; others are able to function more frequently than once a day at noon. Many SCANs are built into other pieces of navigational equipment, such as sextants; such communication devices are invariably referred to by sailors as "sextalks."