On the outbound route of my first solo trip to Izu Oshima, I,Rikutsu-Kone-Taro, experienced broaching for the first time, so let me share that story.
Izu Oshima is located on a straight line connecting the southernmost points of the Boso Peninsula and the Izu Peninsula, making it an island that can be considered the gateway to the open sea. While there are several fishing ports on this island, the only one open to pleasure boats is Habu Fishing Port, located at the southernmost tip of Izu Oshima.
In other words, visiting Izu Oshima by pleasure boat means making a port call at Habu Port. To enter Habu Port, it is necessary to circumnavigate the southern tip of Izu Oshima, experiencing the touch of the open sea.
For pleasure boat enthusiasts, a trip to Izu Oshima becomes a kind of test of skill.
Since deciding to purchase a boat, Rikutsu-Kone-Taro had been eager to realize a visit to Izu Oshima as soon as possible.
It’s about 24 nautical miles in a straight line from the Home Marina in Miura Peninsula to Habu Port. On a day with stable sea conditions, it wouldn’t be too difficult.
Since the delivery day, attention was given to four points: 1) improvement of docking and undocking techniques, 2) mastery of rope work techniques, 3) mastery of GPS, radar, and autopilot usage, and 4) expanding the sailing range with each departure.
Docking and undocking were practiced repeatedly, focusing on the right side only.
Rope work involved mastering two knots, the cleat hitch, and the bowline hitch, using both hands.
GPS changes in display content during scale changes, radar correlation with visual observations, and autopilot accuracy were all carefully noted with each departure.
The sailing range was expanded by referring to previous GPS tracks, ensuring efficient accumulation of experience with each departure.
On the morning of the day when relatively low wind speeds and wave heights were expected (December 30, 2022), Rikutsu-Kone-Taro decided to go to Izu Oshima. The arrival at the marina was around 0900, and departure was around 1030, as far as I remember.
According to the same forecast, there was a west wind in the southern sea of Oshima, so the plan was to head straight south from Tokyo Bay towards the western end of Izu Oshima. Then, gradually change the course to the east after clearing the western end of the island, heading towards Habu Port from the west.
During the journey, the autopilot was used to navigate almost without weaving. Avoiding weaving could save both time and fuel.
Around the time they rounded the south of Oshima, the wavelength and amplitude of the waves on the sea surface increased, and sometimes the bow seemed to almost pierce the water.
Looking back, it seems that broaching occurred at this time. There was a moment when the rudder completely lost its effectiveness, and I felt as if the boat was about to capsize. It was a very frightening moment, but at that time, there was not much awareness of the problem. Ignorance can be truly terrifying.
Nevertheless, even if they had recognized the broaching phenomenon at that time, the nearest harbor was Habu Port.
Anyway, they had to find the speed and rudder angle at which the boat would stabilize and proceed patiently. It was not a journey to rush. Depending on the situation, they were prepared to spend a night at Habu Port.
Listening to music on the radio or Bluetooth, observing the ripples on the water surface, and passing the time.
At times like these, GPS was a blessing. It gave confidence that they were slowly but surely approaching Habu Port.
Even when they should have reached the place where Habu Port should be visible, the entrance to the port did not appear. Waves were hitting the walls of Oshima, visible on the horizon.
The absence of fishing boats around might be due to it being the end of the year (December 30, 2022) or perhaps because of rough sea conditions. A little anxiety crept in.
Since they were approaching the port, they tried to make a phone call to inform Habu Port that they were arriving, but no one answered. Yes, it was the end of the year, and everyone was on vacation. That explained the absence of fishing boats as well, they understood.
As the port entry was imminent, they changed the control of the two engines from independent control to synchronized control, using one lever. Controlling the two engines separately makes turning in a narrow space much easier.
For this maneuverability, it could be said that Rikutsu-Kone-Taro chose a twin-engine boat.
Using the bow thruster as well, the freedom of maneuverability dramatically increased during experiments related to docking and undocking in front of the marina’s guest berth.
Although there are skilled individuals who can expertly dock without a bow thruster with a single engine, reading the wind and tide, Rikutsu-Kone-Taro thought it would take more time to reach that level.
Now, slowly advancing according to the GPS, they saw the tip of the right breakwater heading towards the water source.
Since the left breakwater was not visible, to avoid a collision with the left breakwater, they slightly approached the right breakwater and slowly turned the rudder to the left. However, the bow did not turn left, and a strange sensation was felt in the hands.
Even with the lever in neutral, the right breakwater was getting closer and closer.
For a moment, they thought, “Wait, could there be a malfunction? This is dangerous, we’re going to hit!” So, in order to avoid a collision, they quickly reversed both engines, killing the forward momentum, then increased the rotation of the right engine alone to turn the bow to the left.
Since the bow turned left immediately, they also reversed the left engine. The distance from the breakwater increased.
Thanks to the two engines.
Then, as soon as the left breakwater came into view towards the water source, they adjusted the rotation of the engines to turn the bow towards the bay.
When the bow was stable, facing the inner part of the bay, they finally realized that they had forgotten to cancel the autopilot.
Turning off the autopilot returned the rudder to its normal function and response.
“Ah, thank goodness!”
From now on, they decided to consciously be aware of turning the autopilot on and off.
With the distance from the island taken sufficiently, they turned the course towards the northeast. The wave height decreased, and they could increase the speed.
The further north they went, the more the sea conditions allowed for higher speeds. There were almost no visible ships, and there were hardly any ship shadows on the radar. They gradually increased the engine rotation while ensuring safety.
Oshima quickly disappeared behind them. Adjusting the engine trim angle and trim tab while comfortably running.
They found a setting where the boat could run at about 25 knots with a near-parallel angle to the water surface, so they decided to go with that setting.
The sky, which had been cloudy in the morning, gradually became more sunny, and the soft afternoon sunlight spread gently in the clear winter atmosphere.
It was a stable return journey that seemed unimaginable on the same day they experienced that sea on the southwest side of the island.
As for incidents on the return journey, they lost one fender.
When docking at Habu Port, they adjusted the height of the fender, but the way it was tied seemed to be wrong, and it was blown away by the wind.
Fortunately, since they were able to return within the marina’s operating hours, they docked carefully and bought a new fender.
They gained many points of reflection from this Izu Oshima trip. They decided to improve and enjoy boat life even more.
That’s all for this trip.
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