Advantages of Bottom Speed Logs:
- Can be retracted /lowered faster viz a viz a towed logs.
- Bottom logs do not foul up with surface objects
- Bottom Logs can provide direct inputs to other equipment like Radar, AIS etc.
- Can provide inputs to multiple displays on the bridge or Captain’s cabin etc.
- More accurate
- Measures slow speed also (towed need > 5 kts)
- Astern speeds can also be measured.