Ugly Raw Water Blockages - A Fouling Story

We're spending quite a bit of time in marinas these last few months, as I'm doing some contract work and Admiral Ley needs a safe home while I'm away from the boat.  

This means that our sea water cooled refrigeration and airconditioning systems are running frequently in estuarine waters with a very high fouling capability.

Coming from a relatively cold water background (Melbourne, Australia) I'm still amazed at how quickly an anchor, or chain, or in this case a raw water inlet, can become completely fouled by marine growth in these warm water areas.  The image at right shows the problem - the hose tail at left is almost closed with barnacles, and the hose tail at right has a decent oyster growing - just what we don't want.  

 
When we look at the hose, the situation is obviously worse. Large clusters of barnacles and yet another oyster are almost completely blocking the inlet hose.  Note this is 1.5" (40mm) hose, that feeds a manifold with multiple outlets for refrigeration, air conditioning, deck wash, genset etc.

To counter the problem we now place a chlorine tablet in our raw water strainer every other day, when we're in a marina.  We use standard swimming pool chlorine tablets, that dissolve in just a few minutes after placement.  These do a great job of stopping the growth from the strainer basket onwards.

Special Note :  You MUST NOT use chlorine tablets on a seawater inlet that feeds your R.O. water maker - it will destroy the membrane(s) !

Chlorine tablets also clean up the hoses really well,  but they can't help with the hose and fittings that are in the line before the strainer.  So now we replace that hose every twelve months - a half day boat project that keeps the systems running and my back and shoulders in fine trim (its a b**g*r to get at), and my knuckles suitably skinned.  Boat jobs.

Along the west  Malaysian coast, from Singapore to Langkawi and northwards into Thailand, this type of fouling is all to common.  In Kuah Harbour (Langkawi), the long term cruisers know that you must lift your anchor chain by 4 or 5 meters one day, and then lower it back again the next day, in a never ending alternating sequence, to stop the aggressive growth there from fouling the chain that is between the water surface and the muddy bottom.  This really does work, though nothing will stop the change to the chain galvanising caused by the very special mud in Langkawi.  But that's another story.....

Singapore Straits - Sailing From Malaysia to Indonesia

The Brightly Colored "Lego Barge" Came Over The Horizon This Afternoon - At 2 Knots

We departed Puteri Harbour in Johor, Malaysia at 11.00am this morning, and arrived at Nongsa Point in Batam, Indonesia, at 6.00pm this evening.   Its only 47 nautical miles by sea, but a world apart in many ways.  Our AIS target identification system was kind of busy - over 2000 targets (vessels) tracked in a single day must be some kind of record.  

Our Track Is The Black Line, With Destination Nongsa Point At Lower Right

You can get a very sore neck trying to keep track of all those ships from the cockpit.

Right now, from our berth in the marina we can identify over 420 discrete vessels in the Singapore Straits, all individually identified and tracked on the plotting system.  

The straits are very busy, and we find the AIS system essential for safe navigation here (see our AIS technology primers Part1, Part2 and Part3 for background).

Puteri Harbour had very few visitors, and lacks any useful services except fuel supply, though it is safe, clean and inexpensive.  But I've never been in a marina that was so ....... soul less.

When the wind came up we managed to sail for just two hours today, roughly a quarter of the 8 hour voyage, which is about average for this part of the world.  But the sailing was a delight, a reminder of why we chose this life style.

Here at Nongsa Point the welcome and atmosphere are completely different to Puteri Harbour.  Staff are more competent and confident, and there are active sailors and cruisers on many of the boats here.  The place has a nice buzz about it, with sail training yachts and dive charters moving about the harbour.  The attached resort provides a pool, bar and meals, and the local ferry terminal has regular services to Singapore.  We're impressed.  We'll be here for a few weeks whilst we prepare for the next phase of our cruising life.

Things That Work For Us # 3 - The Powerdive Hookah

Did Somebody Lose Something ?  Malacca Straits Midnight Dive

As cruising  sailors we are definitely not professional divers, but we do enjoy the underwater world.  

More importantly, we often also need to work under the boat for cleaning, maintenance and clearance jobs, when bad stuff happens.  Which it does ...

That rope I'm holding at left caught around our propeller in the Mallaca Straits back in 2006.  Not surprisingly it stopped the drive train and the Cummins engine in a flash.  

Drifting powerless at night, in a busy sea lane, is not our idea of fun, but we were able to clear the propeller and get underway again in quick time, using the Powerdive system.

Hull Cleaning Is Much Easier With Endless Air

Basically its a simple 12 volt powered compressor that provides low pressure air, via a hose, to a regulator worn by the swimmer.  It's incredibly easy to use, and we've had great success introducing people to the underwater world using the Powerdive.  The fact that they are tethered to the boat by the hose is a positive thing ....  even beginners feel comfortable.  The Powerdive compressor also keeps people at shallow depths - go beyond about 5 meters and it just won't pump air to you - so you tend to come up again !