Need help to understand harbor info from Reeds almanac

[dokondr]

From Dielette port information (Reeds almanac, area 18, Central N France):

"Outer hbr entr dredged to CD+0.5m; accessible for 2.5m draft with Coefficient > 55"

Questions:
1) "harbor entrance dredged to CD+0.5m" - let's say hbr.entr was drying land with 2m over CD, so after being dredged to CD+0.5m, it is now 1.5 over CD. Correct?

2) "accessible for 2.5m draft with Coefficient > 55" - what coefficient almanac talks about?

[Tellus]

It seems that you are not the first one..just found an old thread on ym scuttlebutt
Almanac correction - access for Diélette

[dokondr]

Originally Posted by Tellus

It seems that you are not the first one..just found an old thread on ym scuttlebutt
Almanac correction - access for Diélette

This link is broken.

Any ideas what would be the depth after "harbor entrance dredged to CD+0.5m" ?
And what is this "Coefficient > 55"?

[goboatingnow]

Originally Posted by dokondr

This link is broken.

Any ideas what would be the depth after "harbor entrance dredged to CD+0.5m" ?
And what is this "Coefficient > 55"?

This is a French term. Its signifies the relation between. One tide at the next.

70 indicates an average tide > 70 the tides tend towards springs . Less they tend towards neaps. It's used a lot in relation to cill heights.

50 is mean neaps so the entrance is accessible for those draughts from mean neap tides +. The lower the co-efficient the wider range of tides that the depth is valid for.

Dave

Dave

[Stu Jackson]

Those coefficients are not limited to France. We have the same information in many cases for tides & current here in the San Francisco Bay region. instead of tide heights as noted for about 85% of the locations and current strengths for over 60%, the rest are expressed as coefficients, which is simply a multiplier of other figures given in the tables & charts.

Who said high school math wasn't important?