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use the digital lasermeter for fwd and aft draft

Friends !
I have another advice for Surrey draft. You should go to boatswain and ask him a long rod. Then you should fix on the end of this rod your personal smartphone. After that you will go to draft mark for survey on deck. Switch on the smartphone for recordings (if necessary, use touch light) and low down it close to draft mark...
Hope You understand final actions you should do.

erickp21, erickp21, well Iam a chief officer onboard a vessel, im using the 1/3 and 2/3 formula even surveyors use this. If you have manometer it will be simple. Get the Difference in manometer. Then add or subtract the value on midship draft that you get. And then get also forward and aft draft in the shore side. To apply the formula for forward draft simply get the manometer reading then get the difference after that multiply the difference to 1/3 for fwd draft and 2/3 aft draft, then subtract or minus which ever side is listing.
Ex. Your listing to stbd and you get the draft to port side. you get 35cm difference in manometer as for the port side draft fwd=11.9 aft=11.9 mid=11.9
For mid draft simply add or subtract the draft depends where you are listing. See below.. mid draft 11.9m+0.35m= 12.25m,
for forward 0.35*1/3= 0.12cm then fwd=11.9+0.12= 12.01m,
aft 35*2/3= 0.23cm then
aft = 11.9+.23= 12.13m.
If vessel is listing to port you must subtract. Vice versa if you get draft to starboard.

mariners728013,
well I am a chief officer onboard a vessel, im using the 1/3 and 2/3 formula even surveyors use this. If you have manometer it will be simple. Get the Difference in manometer. Then add or subtract the value on midship draft that you get. And then get also forward and aft draft in the shore side. To apply the formula for forward draft simply get the manometer reading then get the difference after that multiply the difference to 1/3 for fwd draft and 2/3 aft draft, then subtract or minus which ever side is listing.
Ex. Your listing to stbd and you get the draft to port side. you get 35cm difference in manometer as for the port side draft fwd=11.9 aft=11.9 mid=11.9
For mid draft simply add or subtract the draft depends where you are listing. See below.. mid draft 11.9m+0.35m= 12.25m,
for forward 0.35*1/3= 0.12cm then fwd=11.9+0.12= 12.01m,
aft 35*2/3= 0.23cm then
aft = 11.9+.23= 12.13m.
If vessel is listing to port you must subtract. Vice versa if you get draft to starboard.

The pilot observed that your vessel is having 2.5 degrees to starboard.Your vessel breadth is 30 meters with draft of 10 meters and 10 knots speed.pilot ask how much actual draft vessel has in relation to vessels list

erickp21, in case you know only the port side draft, and if you want to know the stbd side draft. The solution is here.
if your vessel has digital clinometer, you can know how much degree of list and let it in mind. Then you need to know your vessels breadth.
The formula is tan(list) x breadth= difference between port and stbd draft.
Just remember the breadth means the distance between two draft markings port and stbd. Fwd breadth between two fwd draft marks will be less than mid drafts.

https://www.funnel2tunnel.com/category/cargo-work/
Maybe you can try to find the above site the " not able to find all six draft"
Maybe it can help you.....

mariners728013, Then is there a formula I can use for fwd and aft?

erickp21, By using the inclinometer you can find out the drafts on the other side by simple trigonometry formulae. But that will be only for the midship draft. The forward and aft drafts it will not be possible to do so simple because the lateral distance between the port and starboard marks are not uniform from the keel upwards. while for the midship, the distance between the port and starboard marks is uniform for the entire length from bottom to up.

mariners728013, Thank you so much for the response.
Then yeah, with that manometer running across the beam is as simple as adding or subtracting to the non visible draft.
I asked yesterday a draft surveyor and he explained that using a formula you can calculate the difference in midship draft using a clinometer. I don't know if you have experience with that but I forgot to ask him if the result of that calculation can be applied to fwd and aft as well.

erickp21, You can refer to this book https://seatracker.info/viewtopic.php?t=45424, Regarding the the 2 scenarios, that you have pointed out, In scenario 1 - Using the U tube or as we call it manometer, you can read the visible midship draft and apply the difference in the manometer / U tube proportionally to the visible draft. Eg- if the beam of the vessel is 25metres, then u can have a long transparent tube running from from 1 side to another and kept standing at the shipside railings or u can have a U tubes separated by say 2.5 metres only. so in the case of the tube running the entire beam, the difference in the liquid level between both sides will be same as the difference between the drafts on both sides. While if u use a U tube with a difference of 2.5 metres placed absolutely on the center line, then the difference in water level of the tube will have to be multiplied by 10 and applied to the visible draft. Now regarding the ford and aft drafts, there are ships plans where it gives the horizontal distance from the keel upwards between the port and starboard marks for forward and aft. This can be used as proportional to the beam and distance of the midship drafts and correction applied.
Hope this simplifies the matter. This will help in both the scenarios.

Hello everyone, I am a Draft Survey Student, I normally do Tally Surveys, cargo certification and inspection but lately want to learn more about Draught Surveying.
How do you go about calculating drafts that you cannot see.
I have 2 scenarios:
Number 1: Vessel moored. I can see all of the starboard draft marks but none on the port side.
Number 2: Vessel moored. I can see all of the Starboard draft marks and the ship has a tube on midship that goes from side to side with markings on each side. I can just take that measurement and add or substract to the draft i can see?
Any guides, formulas or books that you can recommend will be duly appreciated. Thank you