I emailed the International Hydrographic Organization to investigate their flag. The IHO conducts meetings and conventions all around the world, so I thought that a flag would not be solely limited to their headquarters in Monaco. In my email, I asked the IHO if their flag (provided they had one) bore the IHO logo over a blue field, and if so, was it the official flag of the IHO.
In responding to my email, the IHO's Director, Rear Admiral Neil Guy, explained to me to that the organisation indeed has a flag that flies over their Monegasque headquarters and matches my description. Here is his response:
The IHO has a flag which is on a blue background and which flies over the Headquarters in Monaco every day. We are not sure whether it was ever really established as the 'official' flag and as a result of your query we will investigate the matter further and make it official if necessary.
It is interesting that, in addition to our flag and the flag of Monaco which are always flown, we also fly the flag of a Member State on their National Day. We now have 70 Member States from around the world.
Thank you again for your enquiry.
Rear Admiral Neil GUY
International Hydrographic Bureau
MC 98011 Monaco Cedex
The International Hydrographic Organization is an intergovernmental consultative and technical organisation that was established in 1921 to support the safety in navigation and the protection of the marine environment.
The object of the Organization is to bring about:
The coordination of the activities of national hydrographic offices;
The greatest possible uniformity in nautical charts and documents;
The adoption of reliable and efficient methods of carrying out and exploiting hydrographic surveys;
The development of the sciences in the field of hydrography and the techniques employed in descriptive oceanography."
Recently, IHO received much publicity when its member states voted to rename a large expanse of water near Antarctica the "Southern Ocean", which essentially "created" a fifth ocean on the planet.