We all have been on ships where the old man does weekly rounds on Sunday of the ship.
Does anyone know where that requirement resides?
Is it a MOSH, regulatory, class, Solas or some other requirement? We can't seem to find it.
Jolly Jack d'you know?

For UK flagged vessels the "Masters rounds" are required to be entered into the official log book.

The requirement comes from a Merchant Shipping Act. What legistlation, if any, required this to be placed into UK law I do not know.

The latest UK version is below.

The Merchant Shipping (Crew Accommodation) Regulations 1997
Regulation 35

Maintenance and inspection of crew accommodation
35.—(1) The crew accommodation shall be maintained in a clean and habitable condition and all equipment and installations required by these Regulations shall be maintained in good working order.

(2) Every part of the crew accommodation, except store rooms, shall be kept free from stores and other property not belonging to or provided for the use of persons for whom that part of the accommodation is appropriated, and in particular no cargo shall be kept in any part of the crew accommodation.

(3) The master of the ship or an officer appointed by him for the purpose shall inspect every part of the crew accommodation at intervals not exceeding 7 days and shall be accompanied on the inspection by at least one member of the crew.

(4) The master of the ship shall cause to be entered in the ship’s official log book a record of—

(a)the time and date of the inspection;.
(b)the names and ranks of the persons making the inspection; and.
(c)particulars of any respect in which the crew accommodation or any part of it was found by any of the persons making the inspection not to comply with these Regulations..

I checked the Canadian Crew Accom. Regs. Not quite the same. I'm on a mission now because I know I have seen it before..probably the UK regs LOL
Thanks!

For ships trading in central Canada, a transit through US waters mean you must comply with Vessel General Permit (VGP), which requires a weekly walk around the vessel by an competent crew (Chief or Captain), followed by a log entry in the VGP logbook.

Not sure if its exactly what you're looking for, but have a look at #62 in MOHS which mentions weekly rounds of certain areas (related to food prep and storage as well as potable water) and logging these inspections.