Sea Trial

Bob Carroll arrived at 9 AM yesterday and we soon got to work.

The first task was to raise the headsail.   He had brought a can of  "CRC Heavy Duty Silicone" spray, which we applied liberally to the bolt wire on the sail and the lower part of the track on the headstay.  The morning headwind and the lubricant made a lot of difference because the lift itself went very well, though we had a couple of minor dramas with the routing of the halyard.

We motored out of the marina and down the La Paz Channel into the open waters of the bay, in a light 5-6 kt wind and away from tidal currents.  There we began go gather data on engine RPM vs speed in knots.  Our methodology was as follows: Head on course 330 T, with the apparent wind about 50 degrees to port, with the engine at 1000 rpm.  We would then would work up the various increments of rpm, waiting for the speed (Speed Over the Ground [SOG], as reported by the GPS) to settle down before making our recording.  We then went through the same sequence on a reciprocal course of 150 T with the wind off of our starboard bow.  After recording data from the first 6 rpm's on this reciprocal course we could see that the results were identical on both courses.

The results are as follows:

RPM .. SOG

1000 ... 2.9
1500 ... 4.4
1800 ... 5.3
2000 ... 5.7
2200 ... 6.4
2400 ... 6.9
2600 ... 7.4
2800 ... 7.7
3000 ... 8.0
3100 ... 8.1

3100 rpm was the maximum that we could achieve.  The boat was about as heavily laden as it will be for the coming cruise (e.g. nearly full water tanks, full internal diesel tanks, 55 gals of diesel on deck, victualizing almost complete) and I expect that maximum rpm to reach the prescribed 3200 in Australia after the boat has been greatly lightened for coastal cruising.

While this motoring was going on I turned on the new Red Dot space heater and found that the air was so hot at the slow fan speed that I could not hold my hand 2 inches from the heater for more that 10 or 15 seconds.  Given that the cooling water circulating at about 195F this was not a surprise, but I was nevertheless pleased to get confirmation that I can expect some serious warmth in the cabin during my passage through the high latitudes (alas, only while the engine is running).

Bob with spinnaker in sock

We then rolled out the jib and had lunch while the autopilot did the steering.  After that came the task of trying out the asymmetrical spinnaker (the one in a snuffer sock).  We turned the boat downwind, with a 7 knot apparent wind. I cleared the overburden on the starboard side of the V berth and was soon feeding the sail to Bob through the forward hatch.  Bob pointed out that we would need a block ahead of the headstay so that we could control the height of the tack above the deck with a line. I dug out a snap shackle and soon had it and the line in position.  After some analysis and discussion we figured out how to attach the halyard.  We then attached the new spinnaker sheets that I had brought back from the USA.  Fortunately we took our time to carefully analyze everything and soon figured out that the sock ring would not be able to rise because the bottom of the sail and the sheets were going to hold back one of the three lifting straps. We sorted this out then hoisted the sail in its sock.

After a final check of proper routing of the sheets we deployed the spinnaker.  Bob raised the ring at the bow while I remained in the cockpit steering and working the sheet.  The operation went with remarkable ease and soon we were making 4.5 knots with a 6 kt wind off our starboard quarter, relaxing while the autopilot did the steering.  I had a beer in celebration.

We then explored the range of wind angle that the sail could handle and soon found ourselves on a beam reach with the wind from 90 degrees to starboard, hiking along at 6.5 knots.

We then eased off the wind and gybed the boat.  I remained in the cockpit and Bob went to the bow.  The plan was to ease the sheet as the stern of the boat crossed the wind, allowing the sail to blow forward of the boat.  When the boat had the wind on the port quarter I would bring on what had been the lazy sheet on the starboard side and the spinnaker would fill with air.  Bob would take care of any problems that might arise up front.  I told Bob that I would make the turn hard and fast.  When we were ready I turn the wheel hard to port, the spinnaker passed around the front of the headstay like a swinging door, and soon we were sailing comfortably on a port tack.  A few minutes later we hardened up on the wind and confirmed that we could carry the kite with the wind directly on the port beam.

At no time did we see a need for the whisker pole, which I'm likely to use only to pole out the jib when sailing wing and wing.  Also, I was pleased to note that the plastic jerry cans strapped on the rails were not causing any problems with either sheets or the roller furler line.

After Gybe

Apparent Wind 10.2 Knots

It was starting to get late and Bob pointed out that the wind had picked up and there were a few white caps in the sea.  We decided to drop the spinnaker and here we encountered more trouble than we had expected.  I steered the boat almost directly downwind and eased the sheet while Bob pulled the ring down the spinnaker using the circular rope built into the sock.  We found that the sock wasn't quite long enough to cover the entire spinnaker and I had to go forward to give a hand.  We got the sock on deck, tucked in  the bottom of the sail, made sure that there were no twists in the sock, then put it down the hatch and into the sail locker.

We motored and did a bit of sailing back up the La Paz Channel feeling pretty good about the outcomes of the day and were back in the slip at about 5 PM.

Bob visited this morning and told me that he had remembered the axiom that the mainsail should always be up when running with a spinnaker.  When it is time to drop the kite the boat is pointed almost directly downwind so that the mainsail blankets the spinnaker, causing it to collapse and making it easier to dowse.

Bob found out from Rick a few minutes later that key to it all is to ease the line holding down the tack of the sail, rather than to ease the sheet.

I don't plan to deploy that spinnaker lightly - probably only if I'm driven to it by days of light airs.  But thanks to Bob's leadership and assistance in the matter I can now consider that spinnaker as another of my cruising tools.