Mexican douse

What is a Mexican douse?

In a big regatta this summer on Lake Leman, about half the boats would approach the leeward mark on a starboard broad reach. This would give them priority over the boats approaching from port. However, the disadvantage is that they had a more tricky manoeuvre to remove the spi pole, fly the spi without it, "douse" the spi at the mark and then jibe round the mark. You are also dousing the spi so it's on the correct side for the next weather mark. This is called the "Mexican douse". For the boats approaching on port, it is simpler as they remove the pole, unfurl the genoa, douse the spi and simply luff up to get round the mark - but will have to give priority to starboard approaching boats.

Courtesy: Schlaeger, Flickr

Why Mexican douse? Apparently, the America's Cup team were practising it and the skipper said that it the crew didn't get the spi down soon, they would end up in Mexico. Another version is that they were pointing towards Mexico.

Notes on how to do it

Last Sunday, two Surprises had a training to learn the Mexican douse. Each boat was manned by two crew making the trip a steeping learning experience, given the Bft 3 conditions.

Helen kindly sent round notes on how to do the douse (courtesy of Philip M). Here they are:

This description assumes we have 5 crew members aboard:
1. No. 1 ("Bowman")
2. Piano ("Pit")
3. Headsail trimmer
4. Tactician (who becomes the "squirrel" during the douse)
5. Helmsman

Jib out. ~10 boatlengths from the leeward mark, depending on speed and crew ability. The tactician initiates the manoeuver by unfurling the jib and trimming it inside the lifelines/pulpit. The tactician handles this because the trimmer is paying close attention to the spinnaker.

Pole down. ~5 boatlengths. The tactician calls for the stowing of the pole. The piano and bowman coordinate the topping lift, downhaul, and stowing of the pole on the boom (or in the cabin). The topping lift and downhaul can be left on the pole if it can be stowed on the boom. The trimmer keeps the sail aloft and trimmed. The tactician and helm are keeping watch for priority issues as the mark draws nearer.

Gybe. The squirrel heads below deck. The helmsman turns the boat around the mark at a rate that is within the capabilities of the crew. The goal is to have a gradual turn, but to round the mark tightly so there is little room between the windward side of the boat and the mark. The piano gybes the jib just before preparing to lower the spinnaker halyard.

Douse. During the gybe, the spinnaker will collapse against the jib. The piano lowers the halyard by about a meter as this happens. The trimmer watches the bowman, and releases the sheet and guy, so the bowman can feed the foot of the sail to the squirrel in the forward hatch. Once the foot is under control, the piano releases the halyard as quickly as possible while the squirrel gathers the sail. The trimmer resumes his position at the jib, and trims to close-hauled.

A video clip of a Santana 35 performing the manoeuver. It's not too different from ours besides the fact that they have 8 crew members, and a pole that stows on the mast:

http://www.youtube.com/watch?v=nXOi9fUYfVc

Hivernal #1 on Lake Geneva

The Hivernal is a series of five regattas over the winter on Lake Geneva. Yesterday, Thierry, Sanja, Ana and I took part in the first one. Heavy rain and no wind was enough to put most competitors off, but 7 boats turned out. The first advantage was gained when Thierry picked out a 180 degree shift in wind so that we tacked early than the boat ahead and sailed past them. By the time we got to the upwind buoy we were in third. We headed back with the spi and it was all over by 2.30. Mercifully, the organizers decided on just one round given the very light winds.

Climate change impacts on Lake Tahoe

As a sailor on Lake Geneva over the last 7 years, I have noticed the warmer water temperatures, lower water levels, increased vegetation. Has anyone else noticed the effects of climate change here?

National Geographic reports on a study published about the climate changes impacts on Lake Tahoe. Given the similar characterics of Leman and Tahoe, I imagine the findings would be similar in Geneva. Has any work been done locally? The study also discusses measures to increase the lake's resilience to climate change.

Sailing on Lake Tahoe

Here is are two main impacts that the UC Davis scientists at Tahoe observed with their instruments.

1. Change in "stratification"
During a typical summer the lake becomes stratified, with warmer waters on top and cooler water at depth. In the winter these layers mix, a process that refreshes the lake and keeps it healthy.
The extended stratification season on Lake Tahoe has major implications for water quality. “A longer stratification period increases the risk of losing oxygen at the bottom of the lake,” Schladow explained, “and this can release a huge, almost infinite supply of phosphorus to the lake in a process known as internal loading.” Phosphorus is the limiting nutrient in Lake Tahoe. The more there is, the more algae can grow, causing a decline in water clarity.

Figure: Lake Tahoe Stratification Season. Source: TERC.

2. Declining water clarity in the summer due to increased algae growth