Originally Posted by donradcliffe
I've got to disagree with practically everything you said.
Firstly, waves come in sets, and it is much easier to see the lulls and the big waves coming when you are outside the surf line--ask any surfer. If you are inside the bar, you need a spotter up high on a jetty or a cliff.
Hanging around outside the bar till the top of the tide is a good idea, but anchoring
in the open ocean on a lee shore is not. The snatch loads on your gear
are tremendous and dangerous, and its just a matter of time before something breaks. You are far better off heaving to.
I'm talking about something other than picking sets and lulls - I'm talking about identifying exactly where the channel is, which is very difficult from seaward
. On many bars, the channel can occasionally shift even in the space of a day or two, so unless you've just gone out across the same bar, knowing its location is crucial when entering (in any vessel constrained by draft
in the troughs). Relying on even expert local information
can be misleading, unless that person has a vessel of similar draft
, speed and handling, and has surveyed the channel since it last shifted.
In a sailboat it's certainly worth trying
to anticipate lulls (ideally you want the maximum lull at the time you're in the worst part of the entrance) but realistically you generally haven't the speed in a cruising yacht to do the whole transit within a lull, so you have to make your decision on the basis you may have to put up with whatever nature dishes up. But you certainly have to know you can stay in the channel.
If you're exiting the bar, and you wait for flood tide (as obviously you must do if conditions are other than absolutely ideal) you can identify the channel (which may have severe doglegs) from inshore looking at the wave fronts, and reassess it in real time.
This is because the steepness of the fronts is an accurate reflection of the amount of current
flowing in the same direction as the waves. The fronts will be much less steep in the channel, where the flood tide is moving the water
in the same direction as the wave energy is travelling. The size of the waves (which is all you can see from behind them) is not much different.
So inferring the location of the channel can be virtually impossible looking at the backs of the waves, especially getting real-time updates once you're committed and entering. At the first sign you have it wrong you must get the bow pointing offshore
as soon as safely possible, at which point you are in the same situation as someone exiting, and can start breathing again.
Breathing not just because you can now see the channel, but also because:
- you won't broach while exiting
- you are very
unlikely to do a reverse pitchpole (whereas a forward pitchpole is a definite possibility while entering) and
- you have positive steering
way from the flooding tide (rather than having it reduced when entering - remembering you're going down a river).
Finally, in the situation where you are exiting 'from scratch', rather than aborting a failed entry attempt: if you touch, the incoming tide will wash you back the way you came, which (by definition) is deep enough. No such escape route
is available on entering.
However you will
be entirely dependent on your engine
, which must be ultra reliable ... and you had better have NO gunge in your tanks
. This is where a daytank can be a lifesaver.
As far as anchoring offshore, it's hardly worth doing if you're just waiting a few hours for a tide. Heaving to makes much more sense in this situation. I was talking about longer periods, such as waiting for daylight, or for an expected moderation of the ground swell.
It's a judgement call, and certainly there are situations where it's a stupid call, but it is often the case that severe conditions on a bar are relatively moderate further out (especially in a long, low swell), and it doesn't seem to me that any favours are being done to apply the label "lee shore" as if this somehow made a place unsafe just because you put an anchor
If it's the sort of lee shore this implies, you shouldn't be there in the first place.
One good way of alleviating the snatch loads from a seaway, (as opposed to the wind
gusts which are the problem in anchorages
sheltered from the open sea) is to add a decent sized buoy (like a 20 litre plastic jerry) to the warp, situating it about where the yacht would otherwise be, then paying out another boat length (a bit more if needed) of warp.
Heavy chain near the anchor
will keep the system working well. The warp cannot snatch straight without submerging the buoy, which takes considerable force.
It might seem like a scope
defeating option (and I can sense armchairs around the world creaking under the accumulated weight of pent up expertise as I write this) but remember that the float is situated where the boat would otherwise have been.
The intensity and direction of loads seen by the anchor are actually less challenging to it, because
a) the new "boat" can submerge, which helps the scope
b) by averting snatch loads, the anchor is helped as well as the boat:
Techniques such as this are used by people in my part of the world who have to anchor routinely in places where there are no viable "anchorages", and don't feature in any cruising guides
. Places like the Bounty Islands, Pitcairn & Easter Island, the Ballenys...