I don't for one minute disagree with your calculations.

Using your criteria, the chart plot places things exactly the same.

However my main concerns are with the relative bearings from Californian at the time of first confirmation that it was indeed a star and not a ship - I used 2300 hrs.

Lord said it was approaching from the eastward- say bearing 090T and eventually showed a green light.

Groves said it was approaching from 3.5 degrees abaft the beam- bearing about 195T and showing a red light.

Now - as I have said already; if Groves is right and you agree we have a radius as a position line - then Californian had to be N x E of Titanic's 2300 position and Titanic had to be approaching Californian from a little west of south. Position line 015-195 crossing 22 mile radius.

On the other hand, if Lord is right then Titanic had to be approaching from roughly 2 points on the starboard bow i.e from the east. If we assume it was 'to the east' then 'to the west is the reciprocal position line. Position line: 090-270 cutting 22 mile radius This cuts your arc position line 2 miles NE of Boxhall's CQD position and 10 miles beyond the collision point.

Plotting your position from Californian does indeed place her about 13 miles north of the collision point but then neither Lord's nor Grove's assessment of direction of approach fits.

You state that the distance Titanic's masthead light was seen from Californian was 22 miles. The nautical tables for combined height of eye give this as 21.55 nautical miles. However this is the theoretical distance.

If you recall, the Californian people waited until they were absolutely sure it was a ship's light and not a star. Every 2.7 minutes Titanic was closing the range by one mile. It follows that if they first spotted something that might have been a light at say 2245 hrs and it became clearly so at 2300 hrs then Titanic would have been 5.5 miles closer. This would then suggest a position line radius of 16 miles at 2300 hrs.(21.5 minus 5.5)

Using that range and Lord's approach bearing would place Californian once again about 4.5 miles beyond the collision point.

Using your position line of NW-SE, it would place Californian 6 miles to the NW, It would again put Groves completely out of the ball park.

My assessment is based on what Lord or Groves claimed. But if we take them right ut of the argument the problem is still there.

For the ship that Californian first saw to be Titanic;, it had to be on that 16 mile radius position line drawn from her DR position at 2300 hrs. It also had to bear within the NW quadrant of the compass. It follows that it greatest distance from Titanic at 2340 had to be 11.5 miles and the least 4.5 miles. I don't think anyone has suggested any of that.

Let me know what you think.

Cheers,

Jim