Saturday, August 21, 2021

HERE WE GO AGAIN

So we’re back in lockdown again from Weds 18 August and it appears this could last a few weeks. From the boating perspective it’s better for this to happen now than later, as we move into Spring next month. It seems it was inevitable that the delta variant would hit our shores and while it’s all too easy to criticise aspects of how NZ has handled the situation (eg the way in which rooms for quarantine are allocated) our infection numbers are remarkably low. If we had the UK’s infection and death rates, then based on the population difference we’d be having 2,665 new infections and 8 deaths daily. While there are sad stories about people having problems returning to NZ, haven’t these people largely created their own problems?

Back to the subject of Cruising and firstly engine servicing.

We’ve used TerraCat for servicing our Cat 3208 10.4L V8 diesels as they’ve had a very knowledgeable engineer who knew our boat well. However he recently left TerraCat and after considering our options we decided to change contractors to Marine Propulsion (MP). The main reason for this is it’s highly desirable to have the same person doing your servicing as they get to know the peculiarities and history of your boat. We weren’t convinced TerraCat could offer this continuity. So far we’re impressed with MP. The engineer who’s now doing our servicing is actually one of MP’s directors (so unlikely to be leaving) and he suggested coming on board a week before the service to familiarise himself with Rapport and discuss our expectations – impressive service. We wanted somebody who will not only change oil and filters, but proactively look for potential issues and provide advice on preventative maintenance. So far we’re very satisfied with our move. For example he found that two pencil anodes in our heat exchangers have not been getting replaced because access is restricted and standard anodes can’t be used. Solution: he’s going to cut some standard anodes down so they fit and then some protection will be better than none. He made suggestions re filter changing frequency to save us cost without compromising performance as well as suggesting we use our spare filters first and replace them with new ones in order to turn the spares over. That’s the kind of engagement and service we want.

Useful tips

1. Barometers

Most of us have nice shiny brass barometers on one of our bulkheads and these should certainly be considered useful beyond ornamentation. So how should we use them?

The barometer’s indicator needle should be reset each morning in order to monitor changes.

If pressure rises or falls 1.6 to 3.5Mb over a 2 hour period it’s warning of a depression.

If pressure rises or falls 3.6 to 6.0Mb over a 2 hour period it’s warning of Force 6 winds.

If pressure rises or falls more than 6.0Mb over a 2 hour period it’s warning of Force 8 winds.

A drop in pressure of 15 or more Mb in a 24 hour period indicates a weather “bomb” is imminent.

As a matter of interest the world’s average atmospheric pressure is 1013Mb

2. Protection from sharp hose clips

Have you ever cut your hands or fingers on the sharp ends of stainless steel hose clamps? I sure have and to avoid this have fitted Clamp-Aid hose clamp safety guards. These are flexible silicone sleeves that easily fit over the ends of hose clamps to provide protection. Cost is about $32 for a pack of 20.

3. Mounting fittings on gelcoat surfaces

At some point we all need to add fittings such as an aerial mount to a gelcoated surface. What most of us do is drill a hole in the gelcoat, put some silicone in the hole and onto the screw and Bob’s your uncle right? Wrong. Silicone has a limited life of around 5 years, so at best water will eventually find its way in to the cavity and migrate into the substrate beneath the gelcoat. The correct way to do this is to drill a hole much larger, in  both diameter and depth than what is required for the screw, fill the hole with epoxy and then drill the screw hole in the epoxy. This will ensure that moisture doesn’t get into the substrate beneath the gelcoat. In any case silicone sealants are not suited to marine applications and we should use marine sealants like Sicaflex 291, 3M4000 or Bostik Simson MSR Construction Adhesive.

4. Paint aerosols

You normally have some paint left in the aerosol after completing your job. In order to re-use the aerosol hold it upside down and press the nozzle until all residual clears out of the nozzle. Then store aerosol upright.

We weren't planning to do much cruising during August, but hope the lockdown is over so we can start serious cruising again from mid-Sept.



Thursday, August 05, 2021

STORM DURING NIGHT OF 2 AUGUST

,During the night of 2 August there was a massive blow in Auckland causing quite a bit of havoc ashore including fallen trees and downed power lines. I recall lying in bed listening to the gusts thankful not to be out on our boat.

Hobsonville marina emailed us the next day advising of gusts up to 67 knots in the marina with some vessels suffering damage to canopies and hatches. Di and I went there to check on Rapport, fortunately finding everything was fine.

Sir Peter Blake’s former 36 metre alloy expedition yacht Seamaster, now called Archangel, which has been anchored for a long time off St Heliers Beach dragged her anchor, but fortunately beached with apparently no damage. Her current owner says Archangel had a heavy anchor and 100 metres of chain out, but there are two issues of interest here:

1. Her owner was not aboard, but able to tell remotely that Archangel had dragged and therefore able to go and investigate. I don’t know what technology the owner was using, but see our last posting re Anchor Watch HD as it shows how valuable this free app can be.

2. Her owner says Archangel dragged her anchor due to a 180 degree wind shift. This is a point I have mentioned many times, that is with adequate ground tackle set (as Archangel had) you are most unlikely to drag in a consistent wind. However when you encounter a 180 degree wind shift – which often happens during storms and/or as fronts pass through, all bets are off. This is because your boat’s movement following the wind shift can pull your anchor out from its set position and just drag it across the seabed. In other cases as your chain moves in the opposite direction it may foul the anchor and drag it across the seabed preventing it from resetting.

But wait there’s more. You have almost certainly anchored on a weather shore, that is with your bow pointing to the shore and no matter how hard the wind blows you are unlikely to see wavelets more than about 25cm high. After the wind shift you will be on a lee shore, that is with your stern pointing to shore and in shallower water. Now the wind has much greater distance to create waves and these can quickly rise to a metre or more. Waves cause a jerking motion placing further strain on your anchor and compromising your security.

Lesson: a 180 degree wind shift is always a case for concern and for close monitoring of your situation.