Have readed a few books from lovecroft, and the fascination of a vague discripted horror seems to be indeed a important thing for him. Your story is superior to his concept because you have a watchdog where build a interesting contrast to the helpless downfall to insanity.
(And I personally had ever the feeling the strange thing on the Titanic-case was not the sinking ship - that's a normal thing - but the Incapacity to act from the Bridge-crew. They took no usual measures to rescue the ship like order to setting leak-sails, building koffder-dam's, or use the pumps in a more sensefull way. For me the creepy element was the paralysis of the crew despite they had a lot time to react)
And of course, great story by the way. Reading is sometimes mental exthausting (also for a guy with firefighter-experience), but I still enjoy it, thanks for your work and afford