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Interpret and compose maritime signals with a tap of the finger for safety and communications. Use it as a practical resource and a learning tool. This application was co-developed with Dr. David Burch, author of nine books on navigation and founder of the Starpath School of Navigation ( and Fellow of the both the US and the Royal Institutes of Navigation.

Knowledge of code flags and related signaling is required on all commercial vessels and recommended for recreational vessels as well. ICOS Plus provides interactive access to the International Code of Signals (ICOS) for both interpreting and sending signals, plus many related resources, including special (NATO) navy signals, international yacht racing signals, and worldwide GMDSS weather warning signals arranged by nation.

Features include

• ICOS: Indexed, hyperlinked, and fully illustrated copy of the International Code of Signals, including flags, lights, sounds, semaphore, phonetic alphabet, and Morse code signals, with instructions on how to use them.

• Interpret signals: Tap in the sequence of flags you see hoisted, and ICOS Plus identifies the signal and displays its definition.

• Compose official signals: Select a standard signal you wish to display from a cross- linked index, and ICOS Plus generates the flag sequence to match it, along with the corresponding Morse code.

• Compose plain text signals: Type in the sequence of letters and numbers you wish to send, and ICOS Plus generates the flag and Morse code sequence to match it.

• NATO Navy signals: Special signals adopted for NATO nations navy use are included and defined, including semaphore signals.

• US Navy vessel classes: A list of US Navy vessel classes identified by hull-number prefixes in included.

• Compilation of all signal flags: A graphic table of all flags in use is given, highlighting flags that have different meanings in Navy applications.

• National flags: All national flags are presented with a unique color-filter option that helps identify them by color pattern.

• International Maritime Organization (IMO) membership indicated on national flags, which usually means they have a Hydrographic Office as well.

• US State flags: All US state flags are presented with a unique color-filter option that helps identify them by color pattern.

• Weather warning signals for US waters: Visual weather signals (lights and flags) that are displayed in coastal stations in response to NWS warnings.

• International weather warning signals: These signals are common to all nations.

• Weather warning signals arranged by nation: The extensive set of all unique national weather warning signals are presented, arranged by nation.

• Beaufort wind force scale: A thorough presentation of the scale is included to help interpret weather signals, including effects observed on land.

• International yacht racing signals: The common flag and sound signals used in sailboat racing are included along with an explanation of each.

• References: A thorough list of references related to international signaling is included.

• Content support: Email queries about maritime signaling and related navigation rules will be promptly answered.

• Other apps from Mintaka Research include the popular NavRules for mastering the Navigation Rules. See