Q122 Study Help

Wondering if anyone has any advice on resources to learn the stability questions on this exam. I have Lapware and other exam sample test resources but I actually need to learn how to do the problems…
YouTube is semi helpful, occasionally.

Are you going to also apply for STCW for Chief Mate/Master? If so, that requires an advanced stability course. That might give you a good background for the stability questions on the license exam.

Thank you for the reply. At this time, per my letter of approval, I will just need the Q122. I am approved to test for 1600ton near coastal, and I will not be pursuing anything further at the moment. I am required to pass:
In prior testings I only had stability questions on the deck safety exam and opted to not learn any of those equations. Now I have this 10 question test that I need a 70 to pass. Having difficulty finding good material to teach me how to do these equations.

Lapware. Call them to ask about that specific stability module. I cannot believe there is much to it.

It’s been quite awhile since I’ve studied, but sometimes I found the methods and solutions in the Captain Joe’s software to be easier to understand than Lapware. Still, Lapware is the gold standard.

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I never used anything like Lapware but the standard text on stability used to be this book, it’s still a good book for the basics.

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That’s a great book if you actually want to learn something about stability, as you should.

But it’s a lot more than you need to pass the USCG exams which seem to be mostly basics and WWII era questions about loading small weights on deck of relatively small vessels.

You need to memorize about a dozen formulas and learn how to attack and defeat USCG style questions. Very little actual knowledge of stability required.

From what I’ve heard that 2nd Mate to Master 1600 exam is ridiculously easy. Probably, it requires no study at all.

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I have this video course which might be helpful depending on your learning style. Feel free to check it out and message me if you have questions.

unfortunately stability on exams is sometimes more about memorizing the “recipe” than it is about stability, but hopefully with some practice problems you will be well on your way.


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Thank you Chris! This looks like it could be what I’m looking for.

Without the STCW master endorsement your domestic 1,600 ton near coastal master license is effectively an inland only license (unless the operating company is illegally crewing their vessels).

The new 10 question 1600 GRT stability test is not difficult and as others have said, is really more of an intelligence test than an actual assessment of the skills you’ll need when considering stability/trim on the job.

Good Resources

  • Stability & Trim: Upper Level by Falck Maritime Services
  • Find as many of the NMC sample examinations as you can and practice. It is likely you’ll see one or more of the sample questions on the actual exam you take.

The main topics covered are:

  • Load line:
    a. Calculate daily burn off by multiplying daily tonnage burned * days sailing and divide by TPI
    b. Find DWA. = FWA * (1.025- SG dockwater)/.025
    c. Add both corrections together and subtract from strictest load line. Ie. If you’re sailing tropical to winter, subtract from winter. If you’re going from a stricter load line to a less strict load line zone you can skip the burn off calculation and only do the DWA.

  • Blue Pages – Constructing Statical Stability Curves to derive righting moment/righting arm, danger angle or vanishing point. Usually involves something like:
    a. Find arithmetic mean draft
    b. Enter hydrostatic curves with draft and extract displacement, KM
    c. Use formula KM – GM = KG to find KG actual
    d. KG assume – KG actual * sin(theta) is the correction
    e. Get GZ uncorrected from Righting Arm curves. Add correction to Righting Arm.

  • Blue Pages – Load to max freeboard draft

  • Blue Pages Displacement in Fresh Water

  • American Mariner (White Pages) – Free Surface Corrections:

    a. Find Weights and i values, correction is i/displacement

  • American Mariner Gain in GM by Ballasting (very easy)

  • American Mariner One compartment Standard (very easy just follow chart)

  • American Mariner Trim via LCG Method- goes something like:

    a. multiply given tons and LCG F.P figures so you have a sum of moments and a sum of tons.
    b. Moments/Tons = LCG-F.P.
    c. Use sum of tons to enter hydrostatic curves and extract displacement, LCB, MT1 and LCF-FP.
    d. The trim lever is (LCG – LCB). Positive value means trimmed by stern.
    e. (The displacement * Trim Lever)/MT1 = change in trim in “. Convert to Ft.
    f. Find FWD trim by (change in trim in feet * LCF)/Length Between Perpendiculars (find from ship characteristics)
    g. Trim lever – FWD trim = Aft Trim.
    h. Extract Mean draft from hydrostatic table based on Displacement. Apply Trim (subtract FWD/Add aft if down by stern etc.)

M.V. Surveyor/ The other work boat – You’re given a stability letter and you load it based on how much drilling mud you may or may not have. They might also ask what the VCG of the remaining deck cargo is: Find max moments, find the currently loaded moments and then solve.


Rolling Period – (.44B/t)^2 = GM
Trim - tan(theta) = w * d/ displacement * GM
Free Surface – r * l * b^3 / displacement * 420 ; (where r is SG tank/ SG fluid you’re floating in)
Shift - w *d/displacement = gg’
TPI - l * b * P / 420 (where P = waterplane coeff.)

That’s all I got/can think of right now. Good Luck!

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Practical Navigator, cheap one time purchase, video tutorials. Worth it.

But what if it’s 99grt vessel

I used this video course to pass the stability module for CMM Unlimited. Worth every penny!