Furuno FMD3100, Operator'S Manual

Page: 215 / 395

12. NAVIGATION TOOLS
12-9
12.7 UKC (Under Keel Clearance)
12.7.1 UKC overview
UKC is the distance between the deepest point of the vessel's hull and the seabed.
The Actual UKC feature continuously checks the ship's draught setting (UKC), and ac-
tual depth.
When a look-ahead area is set and the depth within the set area gets shallower than
the UKC, the Alert 30173 “UKC Limit” is generated. Further, if the actual depth (calcu-
lated from the transducer) is shallower than the UKC, the Alert 30644 "Actual UKC
Limit" is generated.
If the current depth is less than the echo alarm setting the Alert 30801 “Depth Limit”
also is generated. Depth data is required to use the UKC and Echo Alarm functions.
UKC takes into account the amount of hull subsidence (Squat Effect). The evaluation
criteria for Alert 30173 “UKC Limit” and Alert 30644 "Actual UKC Limit" are not based
solely on the distance from the keel to the seabed, under keel clearance or draught.
Note 1: When conducting a route check, UKC is calculated based on the planned
speed for each leg.
Note 2: The sensor value shown is the depth to the transducer. Convert the value to
the distance to the keel.
Sea surface
Draught
Under keel clearance (UKC)
Seabed
Distance from keel
to seabed
Echo alarm setting