Range optimisation thoughts?

vodzurk

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This weekend looks utterly awesome for being on the water... so we're aiming to head out from Portishead towards Swansea Saturday, returning Sunday... wifey really wants us to get to Worms Head again to feed some dolphins if they're there.

But... our safe range on one petrol tank is ~100 miles (mobo). That's leaving us with 1/3 left for error, based on previous trips to Porthcawl at just past planing speed (~17mph SOW), going with the tide in our favor each way. Accuracy isn't great with a small 1" fuel dial.

Swansea doesn't yet have petrol (just called)... they're aiming for next week.

So my thinking is... we've plenty of day if we leave @ 1000h (HW @ ~1030h), take the plumb-line from Porthcawl to Mumbles (conditions permitting), round to Worms Head, sit out LW there for an hour (engine in neutral), Possibly have lunch in Oxwich bay, then head back to Swansea with a bit of the flood... then I make that to be ~100 miles.

My thoughts to you guys are...
  • How much could I potentially extend my range if i drop down to say 5mph SOW, getting a bit free on top of that from the tide?
  • Would an hour or two idling at peak ebb push our safe range up maybe 10 or 15%?
  • Does water in the channel move fastest in the middle? (obviously ducking out if there are any cargo ships).
  • Is this a dumb question, with planing being the optimal speed for a planing boat?
  • Does the tide really give any noticeable boost once near Swansea bay?

We've also got an Aux, in event of massive miscalculation!

Cheers in advance! Will be sure to post an update as the journey unfolds :)
 
Mmm... Turns out Swansea Bay has an airshow on tomorrow, so the marina is probably gonna be rammed, as well as the petrol station. Think we'll just make a day of it and drop hook through LW around the corner from Porthcawl. Maybe see what I can see thru the monocular. Arrr me 'arties!
 
Bah, water got lumpy, so called Penarth and got a berth there for the night.

And 10 mins after making the request... water was perfect again. Oh well, had a nice Penarth pub crawl instead, then chums for company on the way back :).

Wheeee... cheers Sneds, first time we've seen what it looks like when underway!

 
Cracking little boat you have there and it looks like she goes well. I still think you need to try something you can turn the engine off and feel the wind take you where you want to go in silence... I do appreciate that you get places a hell of a lot faster then I do though!

Am I right in thinking if you're a berth holder at Portishead you get X amount of nights at Penarth?
 
Yeah... If I had more time available, I'd be well up for sailing. But time is my problem. I like with motor, you can largely just point it in a direction and go.

Next boat... Diesel and bigger fuel tank. Not in any rush to change though... Been a busy year with overseas holidays arranged by wife limiting our time aboard :(. Wanna make a good go of it when the time is right and visit Ireland and France.

Plus, we could always throttle back and let the tide take more effect.

Yup, berth holder @ Portishead, with 30 days allowed in Penarth. Think the marina group was acquired by a bigger group recently so might have free access to more, I need to check that out.
 
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Even with a sailing boat I always have about a jerry cans (of diesel) on board as well as main tank. When long ago I had nasty Volvo petrol petrol engine I had maybe 3 gallons of spare in a 22 footer. Not much fun refuelling if waves lumpy but if its just range you want much better to refuel main engine at a quiet spot rather than switch to aux. Keep ranging :encouragement:
 
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