Wednesday, 9 June 2021
Wednesday, 23 December 2020
So sorry for not making a proper blog entry. Summer 2020 we sailed from Grimsby to Eyemough in Scotland and back. Harbours included Scarborough, Whitby, Hartlepool, Blythe and Amble. Sarah and our kittens were there Grimsby to Scarborough and again for a week in Whitby. For the rest I was single handed.
You can see photos on my Google Photos album
Sunday, 17 May 2020
|The whole Davis 25 with the prismatic monocular fitted|
I paid only £2.69 for this on Ebay, they have gone up to abut £5 now. Just search for 8x20 miniature monocular.
|The new prismatic monocular fitted, and the standard "x3" (in practice more like 2x) telescope underneath for comparison|
|Showing how the mounting works|
|A dimensioned photo from another ebay listing|
|More ebay listing photos. The optics are coated and so the objective appears orange from outside. In practice the magnification is more like x5 thanx8. Don't trust the description!|
Thursday, 15 August 2019
The problem that exercised me was that we had a way to construct the most likely position, the symmedian point, a neat way that we could draw as it is a "triangle centre". But what about an ellipse of equal probability, that is the set of with the same sub of squared distance to the symmedian point. Were the focal points triangle centres? Did the axes of the ellipse go through other triangle centres?
I looked at the Encyclopedia of Triangle Centres but couldn't make any progress. So I asked its editor Clark Kimberling, who asked Peter Moses. These two are the worlds experts on triangle centres. Peter came back with several triangle centres on the major and minor axes. We did some more work together and the result has just been published in The Journal of Navigation. The Geometry of Elliptical Probability Contours for a Fix using Multiple Lines of Position.
Recently I was in the US for work and got to go to Frank Reed's course on Lunars. at Mystic Seaport. I highly recommend the course and as well as historical interest shooting lunars is a great way to practice getting accurate sextant readings.
..so why aren't we sailing? I hurt my knee working on Tui earlier in the year and I am waiting for it to have recovered enough...hopefully soon.
Monday, 11 June 2018
Photos of it coming out a few years ago and on a trailer. Also comes with box of spares and paper manuals.
Saturday, 23 September 2017
and I thought it might be worth posting here as well
If you need an HF/MF radio for safety because of the area where you cruise, specifically sea areas A2-A4 (out of VHF range), you need it to be DSC equipped, which basically means an (Icom) M801 or M802 at the moment. The reason is that you can call for help to ships outside VHF range and they keep a continuous automatic watch on DSC MF/HF. If you have that need, and hence get the marine radio, you can use the same radio on ham frequencies if you have an amateur license. They are not quite as good as a ham radio as they are more awkward to use for spinning the tuning knob to find some one transmitting, but they will do. There is loads you can do with a ham radio (or a marine radio on ham frequencies). Ham nets, Winlink mail, sailldocs, loads of different ways of position reporting like robust packed APRS and WSPR. You can talk to random hams around the world and they will think its cool to be talking to someone "Maritime Mobile". Of course some of this definitely contributes to safety as well as fun. For those thinking of taking their ham license it is well worth it if only that you understand radio including propagation and fault fixing much better than a typical course for a Long Range Certificate that qualifies you to operate a marine MF/HF radio (even when this qualification is very serious, like in the UK, with a long practical test by the CG, mainly on distress procedures and a written exam). There are also email services (sailmail) and nets for cruisers on marine HF frequencies. I think this is where cruisers are tempted to, often illegally, use a ham radio only not a marine one. It is usually possible to open them to transmit on these bands. A slight word of caution that the performance might not be the same as on ham bands for which the radio was optimised. Also if you had a ham radio on board it would be a wise precaution to open it to marine (and aviation) MF/HF bands just in case. But these days there are very few places where anyone maintains a listening watch on marine MF/HF voice frequencies. You may well be better off shouting for help on a popular ham frequency and asking them to relay it to a MRCC by telephone in that situation.
Saturday, 9 September 2017
We had an 8 hour run to Scarborough. Literally a run with the Genoa poled out. We were pleasantly surprised that with care we can get in to Scarborough at low water neaps. I thought it was much less accessible.
Whitby was only three hours further up the coast and as usual the bridge keeper, the harbour master and the marina all work together to make sure you know where you are going.
We noticed that the river Esk above the viaduct looks suddenly very rural so we took the dinghy up stream and were rewarded with the sight of fiver herons, and egret and a king fisher catching a fish.
We could see from Maine Traffic that Specksioneer tended to go about 7.5 nm off shore for both morning and evening tours. We decided to do the same and as we passed Specksioneer in the harbour Brian said to call on VHF ch 8 when we were both out there. We learnt that the herring spawn at this time of year and everyone is out to eat them! We saw minke whales surface a few times as well as seals and lots of sea birds. It was a great day for wild life watching - and a bad day to be a herring!
|The poster for Whitby Whale watching|
When the wind turned we headed back, stopping again at Scarborough where we saw a harbour porpoise.
With a beam or close reach, and the tide against us more than with us it took 9 hours back to Grimsby timed nicely with the lock on free flow. Unfortunately one mile of the Fish Dock our engine suddenly stopped. We had 40 gallons of fuel so I knew it wasn't that. Cranking the engine to try to restart melted the cable terminal on the starer motor solenoid. We called the CG to tell them of the situation before it developed in to anything dangerous, put up the mizzen and unfurled some genoa so we could heave to. A friendly wind cat Eden Rose kept station with us and could not tow us to Fish Dock as they were too wide, but offered to tow us to Victoria Dock. We could have sailed to anchorage like spurn point. But no guarantee I could fix the engine at anchor. The CG called Clethorpes Inshore life boat who came very quickly. We sailed closer to the lock then they towed us in to moor on the fuelling jetty at HCA. A nice piece of towing with a small inflatable and a 40hp outboard. Once there the problem was found to be a fuel blockage in the primary filter (as well as the burnt out cable on the starter)
|The crew of the Cleethorpes RNLI D-class lifeboat James Burgess II|