5 Expert Tips: Tidal planning and strategy

“We’re all tadpoles swimming in a stream,” says Tom Dolan of single-handed offshore racing. With so many human, technical and environmental components feeding into total efficiency on the race course, Dolan is at all times methods of simplifying any course of that he can.

One key space is knowing the advanced tidal stream situations confronted on each leg of the Solitaire du Figaro. With the scoreboard primarily based on combination time, each second issues. Dolan applies a couple of key guidelines of thumb to assist analyse strategic and tactical conditions – even in brutal crusing situations the place he’s doubtless quick on sleep and seeking to handle his power ranges as effectively as potential.

On this prolonged ‘5 Suggestions’, Tom shares his knowledgeable recommendation on how you can assume clearly in advanced situations, and be probably the most environment friendly tadpole within the tide potential.

Set priorities

Once you’re crusing short-handed and quick on sleep, you might want to hold issues so simple as potential. I’ve a pile of strategic priorities I hold uppermost in my thoughts. I checklist them right here in no specific order, because it’s at all times shifting in line with altering circumstances.

If situations change, the order modifications. After we cross a mark, once more the order could very nicely change. If we discover ourselves defending a lead, the order would possibly change once more. They’re: synoptic wind; native results; sea breeze; tidal present or shift; your opponents; and race course geometry.

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Alter for level of sail

The place of tide within the pyramid of priorities is determined by quite a lot of components together with the energy of the tide, the energy of the wind and your level of sail. For instance, the lighter the wind the extra necessary the tide turns into, so the upper it strikes up the checklist.

The purpose of sail can be important. When crusing upwind in opposition to the tide, the wind and the tide are in the identical path, so this decreases the obvious wind flowing over your sails. Not solely are you crusing in opposition to the tide – which slows your floor pace – however you’re additionally crusing in much less wind which reduces your floor pace. So usually talking, when crusing upwind, the tide will get bumped proper as much as the highest of the pile.

Crusing downwind is somewhat totally different, as wind and tide are opposed, and the obvious wind flowing over the sails will increase. The Figaro 3 is a lightweight boat and the polars take fairly a steep bounce when crusing downwind. So a rise or lower in wind pace or a shift in wind path can relegate the tide to second or third place on our pyramid.

In each instances, wind and tide are collectively or opposed, so the zones of stronger or weaker circulation are fairly simply seen over the water in lots of instances, and may also be marked by lengthy banks of seaweed. Similar to clouds within the sky to inform us what’s happening with the wind, seaweed and waves can act a bit like clouds within the water.

One other necessary factor to observe is the topography. Steep contours trigger water to speed up, so it may be very useful to intention for, or keep away from, steep drops within the sea mattress, particularly alongside sandbanks or mostly between 30-50m alongside the coast of the Channel.

Slack interval because the tide modifications path could be essential – within the English Channel the tidal shift at all times arrives from the west

Time the slack

The interval of slack because the tides begin switching path is a essential time for vital positive factors or losses. The timing of this era can fluctuate so much relying on variation in atmospheric strain and the way lengthy the wind is blowing in the identical path. So search for each indicator obtainable to make the very best judgement concerning the timing.

Within the English Channel the slack, or tidal shift, at all times arrives from the west, so your west/east positioning could be an necessary issue. Boats within the west will at all times prolong or compress, particularly if crusing upwind, so it’s necessary not to attract conclusions about boat pace at moments like this.

Consider wind

In addition to wind energy, tidal streams even have a big impact on the wind path that you simply expertise on the floor of the water. We name this the ‘tide wind’. There are sophisticated vectors that we will use to calculate this shift, however a straightforward rule of thumb is that the ‘tide pushes the tail of the wind’.

Extremely detailed tidal information is obtainable from Barotropic, however can overwhelm boat computer systems

For instance if the wind is northerly, and the tide arrives from the west, the wind will shift proper. The lighter the wind, or the stronger the tide, the better the shift.

Adrena will calculate this within the routing, and likewise has an excellent fixed wind perform which lets you set a given wind path.

After we cross the Channel in a straight line, the golden rule is to by no means wrestle in opposition to the tide, so set your magnetic heading initially and observe this quantity. On quick boats just like the Figaro 3 which speed up simply while you bear away by simply 10° or 15°, it may be good to go a bit excessive in your trajectory.

Nevertheless, on extra typical displacement boats, various course is unlikely to translate into a lot of a pace achieve.

Use outdated nav abilities

Though I don’t truly use paper charts any extra, I feel my background of utilizing paper charts helps me with rock hopping. I did three years of Mini Transat campaigning the place we had been solely allowed to make use of paper charts, and I feel that background offers me the extent of information and confidence to go in somewhat bit nearer to the shore and any shallow areas in contrast with a few of my rivals.

The power to have a look at a rock in actual life and relate it to what you see on a display screen is an important instrument while you’re looking for to flee the worst of an adversarial present. And keep in mind, when you’re rock hopping, you’re greater than doubtless crusing in opposition to the wind. Your floor pace is low (most likely simply 3-4 knots), so a collision most likely is unlikely to trigger that a lot injury!

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