IWC Portugieser Yacht Club Moon & Tide

The new IWC Portugieser Yacht Club Moon & Tide features a new complication by the brand. Taking inspiration from its exploration and navigation past, the Portugieser Yacht Club Moon & Tide captures the time of the tides and its severity in relation to the Moon.

IWC Portugieser Yacht Club Moon & Tide

The Case and Dial

Cased in 18 K 5N gold case, the 44.6 mm luxury sports watch is fit with a rubber textile strap and is water resistant to 6 Bar. It is fit with sapphire crystal on both front and back, with anti-reflective coating.

The case finish and shape is in line with the Portugieser collection, but with a sharper slope taper on the lugs due to the thicker case, at 13.4 mm. The case thickness is due to the tide module added to the base caliber, which in turn also helps with the water resistance of the watch.

The blue sunburst dial uses the same stylistic cues, with roman numerals and railroad minutes track. But to make the watch look more sporty and tool-like, an additional subminutes track is added at the rehaut. But since the watch is not a chronograph, the rehaut scale maybe more aesthetic than functional. The subdials are nicely positioned, and a hexagon screw head ‘fastening’ of the tide subdial reminds the wearer that the watch is a navigational tool.

Lume application is added to the hour markers as well as the leaf shaped hands. The dial is arguably cluttered, possibly a design choice to fill out the otherwise large dial. There are 2 minute marker tracks, 2 hour applique indicators, 2 subdials, and an oddly placed date window. The date looks most out of place on the dial.

How the Moon and Tide complication works

The Earth rotates on its own axis once every 24 hours and, within that period, moves under the two bulges of high tide and two areas of ebb tide.

During the time it takes the Earth to complete a rotation, the moon progresses a little bit further. So, on Earth it takes 24 hours and 48 minutes for the moon to be in the same position. The time between two high tides, then, is always exactly 12 hours and 24 minutes. If, for example, it is high tide at midnight, the next ones will occur at 12.24 and 0.48, respectively.

The tide display on the Portugieser Yacht Club Moon & Tide now shows the slightly shifting times for high tide on the dial. During the 12 hours and 24 minutes between two high tides, the display rotates by around 24 minutes on the 12-hour scale. The energy required to turn it is channelled by the base movement’s hour pinion. The challenge facing the designers was to convert the rapid hourly rhythm into the much more leisurely rotation of the tidal disc. A reducing gear comprising three precisely calculated cogs slows the rotation to the point where the tidal disc rotates around its axis once in exactly 14.76 days. The tidal display module is integrated into the 82835 calibre and contains just 49 individual parts.

Because the display rotates continuously, it always shows the approximate time of the next high tide. If the arrow points to 12 o’clock at 10 o’clock in the morning, the next high tide will be a little later than 12 o’clock because, in the next two hours, the tidal disc will also move a little further. On the opposite side you can also read the approximate time for the next low tide. The exact times for high and low tide depend on the longitude. As a result, the display needs to be calibrated once using the tide tables for a specific location, such as New York, Lisbon or Sydney. According to this, the deviation is theoretically only 10 minutes in 100 years. The display works reliably on all coasts with two equally strong high and low tides per day.

Another special feature of the Portugieser Yacht Club Moon & Tide is the double moon phase display. It has been extended to include a special inscription and also provides information about the strength of the current tides. At full and new moon, the Earth, moon and sun are in a direct line. In this constellation, the tidal forces are cumulative and generate a spring tide – a particularly strong high tide. At half-moon, however, the sun and moon are at right angles to each other. The result of this is a weaker high tide, or “neap tide”. Exactly how high the water rises depends on the geographical location and the exact physical nature of the coast. While the tidal swell on the open sea is only about 30 centimetres, the sea level during high tide rises by up to 20 metres in the Canadian Bay of Fundy. So, anyone in charge of a boat would be well advised to take a look at the dial of their Portugieser Yacht Club Moon & Tide.

Powering the watch is the IWC-manufactured 82835 Calibre. Armed with 60 hours Power Reserve, the self-winding movement beats at 4 hz and uses 25 jewels.

Concluding thoughts

IWC is quite the master at creating modular complications. Their approach to product development and movement management is an art in itself. We applaud the creativity in coming up with relatively simple modular modifications yet meaningful complications like this Moon and Tide Yacht Club. Priced at CHF 35’000, the watch is placed between the new 42 mm Portugieser Perpetual Calendar and the 44 mm version at CHF 33’000 and 38’000 respectively. No doubt there are many other options available at this price range, and it is unlikely that this piece will be a future icon. But for the novelty and fun of reading the tide, the Portugieser Yacht Club Moon and Tide will make a fun toy for Yachting enthusiasts and boat owners.