A reminder to all to check/clean/ replace your raw water intake hose to ensure your next expedition is hassle free

[John Herrmann]

On our recent return from the Whitsundays (Qld, Australia) to the Gold Coast south of Brisbane (675nm) we encountered several (at least 6) occasions and generally at a bad time when we got an airlock in the raw water system. 

Luckily we picked up the change in exhaust note very quickly so hopefully no damage was done. 

The temperature alarm was never activated but extra smoke as well as the changed exhaust note were a dead give away. As our Yanmar 3GM30F has now achieved over 7,600 hours we are very conscious of things that could go wrong but she has been great so far with regular service etc.

After the first scary occurrence I checked the pump and the hose and all was clear. I also 'blew' down the hose and could hear air bubbles coming out under the boat at the intake so all 'seemed' good.

However during a day of bad seas we once again had issues 4 times resulting in a very long 13 hour day to our next port. At this next port we changed the raw water strainer as it was the original (1991) and it did have some corrosion with air leaks a possibility. We had already replaced the hose with a clear one between the raw water pump and the strainer at the service before we left for the return journey.

The rest of the journey was mostly in calm water although again during a rough stage we did have one more occurrence.

Now safely back home I removed the raw water hose to find the first 300mm (foot) totally packed with STUFF. Not sure what it is but could be bits of compacted rubber from the hose deterioration (which possibly hadn't been replaced in her 25 year life) combined with sea life etc but there is no way that the water had a clear run to the strainer.

I replaced the hose with a clear one (a very good idea so as to just visually check any similar intake of plastic bags, jelly fish etc etc).

The extra flow is just fantastic and i'm sure the motor is running a couple of degrees cooler.

So, please don't be like me and check everything else and ignore replacing/checking old hoses to ensure your journey is hassle free.

John

Blue Cristal

(A Beneteau Moorings 38, 1991)

PS Unfortunately the wind was either straight on our bow or non existent resulting in a trip requiring the use of the motor for 132 hours to enable us to reach a port as we do not sail at night.