Showing posts with label tide. Show all posts
Showing posts with label tide. Show all posts

Tuesday, December 3, 2024

June cruise 2024, (Trip #20) Day 1.

The weather forecast looked good so launched Teria on Sat 8th June, early afternoon at Ross River. 

Ramp B launching

Car-trailer park

Ross River motor out



Favorite tea towel - Also a cabin window curtain

Ramp B lee pontoon wasn't too busy, but being a weekend with lighter winds meant allot of power boats were already out although plenty of cars/ boat trailers were parked at the recreation boat park, it was still only about half full (Its a big facility, run by city council). ( Could have tried the coast guard boat ramps at Ross creek in town (Run by Port of Townsville), it's good but bet it would have been 110% full, with cars up on the grass nature strips)

At the mast raise spot, seaward of the port bridge, there were allot of boat wakes rocking Teria about. A shoulder injury had kept me landbound for ages but had finally healed enough, so was happy to be able to rig up between boat wakes, and held on when they rolled Teria around. Good weather weekends are not good times to go out, couldn't get away from the "hell swarmers" fast enough. It's a good motivation to launch/retrieve only on Monday to Fridays in future, if possible.

Rigging up spot - Ross River entrance

Motored out into a 10-15 knot eastery and unrolled the jib only, to motor-sail leisurly over to the Duckpond anchorage not far away.

Motor-sailing

Townsville port

Port of Townsville -  HMAS Adelaide docked.

This trip was a test run for 3 new things aboard. A tide watch, Trangia 25 cooker, and fully fledged ST1000 tiller-pilot with it's extended arm.

The combination of tide watch (and tables) and fishfinder was great for selecting the best anchoring position. Very little chance of "drying out" at low tide anymore.  Found a shallow spot inshore of the anchored fleet of cruising yachts, near a couple of cruising ecatamarans and a motor cruiser (the "2-foot draught club"). It was closer to the protective rock breakwall and further from any wave action. 

Tested the Trangia 25 stove in galley box in cockpit. Used the gas burner mode, which was very fast to boil water and re-heat pre-cooked food. The gas can be turned down and there was excellent flame/heat control from the gas valve. It was outside the cabin because didn't want to risk gas getting inside/staying in the bilges (explosion hazard)








Safe anchoring depth, fish icons activated.

Tide watch, Spring tide low but rising.

Crescent moon at sunset

Day 1 - Ross River to Duckpond, Townsville, Qld.














Monday, December 2, 2024

World tidal ranges

 I was curious to learn about what the tidal ranges (High to low tide fall/rise) around my area were. Then found a good GIS website with the data for the entire world. It's color coded and just click on an area to see how much tide they contend with. (Now we know another reason why the mediterranean sea is so nice)

World tidal ranges - ARCGIS map viewer


Australia - tidal ranges map

World tidal ranges GISmap

It's easy to use. Just scroll mouse to zoom in-out. Pan by holding left mouse button down and move. To see tide range box in area of interest, move arrow to area, left click mouse button.

I'm interested in tidal ranges, mainly for anchoring and tidal current purposes when out sailing. Or if trailering long distances to new cruising grounds around the australian continent/big island.

Around my sailing area, Townsville it's about 3.2m medium range on average. Cairns 2.6m. Northern Whitsundays 3.7m. Mackay/southern whitsunday islands is high range at 5.7m. Kepple Island/rockhampton >5m (and between the last two it's higher..maxing out at 12m top of shoalwater bay!)

Further south Standy staights-Brisbane, its ok/medium again 2-3m range.

Sydney around 1.7m, nice!

Melbourne, Port Philip Bay and around Hobart, Tasmania it's low range, just 1.2m , nicer!

Tide range Port Philip Bay, Melbourne, Victoria is 1.2m (and Bass Straight ~3m)

Perth WA, even lower range, only 0.8m, brilliant.

The remote North West coasts of WA (and NT) have huge tidal ranges (7-12m). Even Darwin, NT is around 7m.

Across the Tasman sea in New Zealand, it's pretty good, moderate to low ranges, on the east coast (best sailing side). Auckland has 2.4m or so. Other areas its low-med range, 1.0m at Wellington. Christchurch-Dunedin, South Island <2.0m.

NZ tide ranges

Mid-pacific Ocean has a 0.3 (One foot) very low range tide zone. It covers Cook Islands and Tahiti (French). Another good reason these are favorite tourist dream destinations with picture postcard beach scenery. 

Mid South Pacific ocean, "one foot" tide zone.

European Tide ranges map

The Med, Baltic and Black seas (and Red sea, off map) are have low tide ranges <1m. UK has high ranges, (so alot of bilge keel boats and crusty old salts over there, ;-))




North to Central American tidal ranges map

Nice low ranges in the Carribean and Gulf of Mexico (Another good reason for enginless square-riggers favoring this area in the Pirates of the Carribean era, less chance of wrecking a ship, argh!). Good on the US east coast (except Bay of Fundy, worlds highest range?). West coast US is moderate range mostly, but it gets med-high range up in BC Canada.


SE Asia tidal ranges map

Nice low range tides in the sea of Japan.  High ranges on Western Korean peninsula and Eastern China. Moderate to low ranges elsewhere in SE Asia.



Thursday, November 28, 2024

Tide watch and Tide clocks

 Bought a "tide watch", a casio G-shock (A$160).  The tide watch indicates the phase of the moon (neap or spring tides) and also a graph to indicate what the tide level was doing in present time (rising=flood tide, falling=ebb tide, high tide, low tide) 

Casio G-shock tide watch. 

It's really just a general indicator and tidal accuracy is plus or minus 30-60 minutes around around my area. The tide tables still need to be read, for accurate high-low times and levels. But the watch is great for general critical tide information at a particular time/date, which can help influence navigation decisions for the better. 

A caveat before rushing off to buy a tide clock/watch. They only work in certain regions and are useless in some areas. A tide clock map of the world need to be looked at first. My sailing area is on the borderline of where tide clocks work. They need to be in semi-diurnal tide zones. These are two highs and two lows per day with similar low and high levels. My area and north to Cape York peninsula (Cairns etc) has "mixed tides", the two lows and highs per day are different levels. The tide clock still works but isn't as accurate, could be plus or minus an hour or so out, but its still good enough for my needs.

Referring to the tides types map below. It looks like Australia's east coast/Tasmania and all of NZ coasts are good. Most of the Atlantic ocean coasts are ok. A fair bit of SE Asia is ok too.

Don't get a tide clock or watch if you live in Perth, Western Australia. Gulf of Thailand. Gulf of Mexico. Diurnal tides occur in these places (Only one high and one low tide per day).

Mixed tides are in Southern Japan, west coast USA, Carribean and Indonesia. So the tide clock watch won't be as accurate there and you might want to talk with locals/fishermen etc in those areas about it first.

Tide clocks only work accurately in the "green" semi-diurnal tides areas. 

TIDE CLOCKS (quartz, analog)

A few month's earlier...

I was looking into "tide clocks". These are also a good way to go and can be bought online for around $60-350 AUD. Some trailer sailers have them on a bulkhead where they are easy to read, as most of them have a 4" to 8" inch (100-200mm) diameter clock face.  They have a specialised clock mechanism that has 12.5 hour half days which is in line with the moons cycle.

I'm old school and like to see the product in a shop, however up in the reletively "remote" coastal cities/towns of NE Australia, with mixed tides, they are very rare items in stock. On a road trip to Cairns, 400km north of home base, visited "Whitworths" marine chandlery, a very well stocked sailors dream store. They had a plastimo keel boat tide clock, for long distance yachties, a very well built  heavy, solid, high quality piece of kit with a matching $350 price. Its face was only 4 inch but it was a bit too bulky heavy for a small 18 foot TS, it would be great in a bigger boat like a 25-40 footer.

Plastimo tide clock - 10cm chrome, Whitworths.


There were some nice ones online too. Like 20cm budget stainless steel case ones made in Northland, New Zealand. Cruising electronics - Rarity and Hansen. They also have a nice "time and tide" clock, very well priced. 

Rarity and Hansen 20cm tide clock, NZ.



Rarity and Hansen 20cm "time and tide" clock, NZ


(NZ a world cruising hotspot area, especially during the south Pacific cyclone season, so its well serviced for marine gear and yacht refits). (They also have "Royal Mariner" the heavy-duty good stuff, on par/price with the plastimo one).

TIDE WATCHES (digital).

As a TS is so small with limited space, i discovered and looked into digital tide watches. These range from economic simple $100-$160 eg Casio's. to complicated bluetoothed computers for surfers and Rolex challenger athletes, costing many hundreds of dollars on upwards.

The 2023 G-shock tide watch was the only budget one i could find in jewllers up here, it has a stated 2 year battery life, but it might last longer if the red LED light isn't used much.

(Tried to find the cheaper/simpler superceded 10 year battery life 2022 model, which was a nice round shape one advertised at BCF, but as usual nothing in store) They can be found second hand on ebay etc, if willing to take a punt.



My G-shock watch is very lightweight, so it's almost unnoticeable to wear. However it is very robust, takes 20 bars underwater pressure (200m = 666 feet) and is an accurate time piece. It's 52mm width makes it easy to read.

It has far more functions than the earlier WS1300H, most of which i will probably never need or use (stopwatches, timers, alarms etc) (Casio, please bring a simple cheap tide watch back..) I just like seeing what the tide is doing at the present time, and where i am in the tide cycle, how many hours to the next low or high tide). Usually that time is when aproaching anchorage or a tidal estuary, places likely to run aground in the near future (and how much caution to apply to navigation, eg more cautious on a falling tide)

(For tide/trip planning say day or two ahead,  tend to use my mobile phone app's or the hard copy tide tables while resting at anchor, sometimes the coast guard tells you weather/tide info on VHF radio) Still all the inbuilt functions might be good for others who love tech and don't have tide tables/VHF's etc on them.

G shock tide watch. Comfortable to wear and easy to read.

 G-shock tide watch. waterproof strap design

It's also handy having this tide watch for any beach related activities. From walking the dog to going for a swim or surf,  fishing, snorkelling or travelling around on 4WD coastal road trips.