Standard Features Applications Together with an EM-Log or other log sensor measuring the Speed Through Water (STW), the SATLOG SLS 4120 becomes a central display for speed rela- ted information such as Speed Through Water and Speed Over Ground, as well as distances travelled. For more details visit www.marinemegastore.com or call 0871 8732404 1 For more details visit www.marinemegastore.com or call 0871 8732404