(1) The bare vessel without any stores or weights before going to sea
(2) The vessel loaded ready to go to sea
(3) Fishing vessels when they arrive at their fishing ground
(4) When they finish their fishing trip with 20% maximum catch onboard before leaving the fishing grounds
(5) Before they arrive in harbour with 20% maximum catch
(6) When they finish their fishing trip with 100% maximum catch onboard before leaving the fishing grounds
(7) Before they arrive in harbour with 100% maximum catch

Every vessel must check their vessels if taking a heavy load onboard to make sure the vessel does not become top heavy, making the Centre of Gravity to rise up maybe above the Metacentre giving the vessel a capsizing lever.

Caution must be maintained regarding a vessels stability when working North in winter months, Ice accretion can easy catch an experienced seaman out, never let ice accumulate on your vessel, this will give you an angle of loll.

Cargo vessels have to make sure they can carry any materials by working out the area they have in their hold and working out the mass of the material they're going to be taking aboard to make sure they can take that material, every material has different masses

Fresh water has a mass of 1.000t per metres cubed
Sea water has a mass of 1.025t per metre cubed
These figures are important for summer and winter loadlines on cargo vessels
While coming into port with a fresh water river, if the vessel has been loaded up to her maximum loadlines in a port that has sea water she will sink in a port with fresh water.

If your doing modifications to your vessel, get a stability captain down to make sure your vessel is safe to go to sea, your altering the vessels stability, you might capsize.

A lot of vessels have been lost because of the effects of F.S.E.(Free surface effect) F.S.E. makes your vessels GM smaller and is very dangerous
Try this for a demonstration of F.S.E.
Place a half full plastic lemonade bottle on the flat of your hand
don't grip the bottle and let the liquid move slowly
It will fall off your hand
Imagine what this does to a vessel!!!!!!!!!!!!!!!!
Keep F.S.E. to a minimum.
Keep all water tight doors and hatches closed while at sea.
Keep the bilge's dry.
Never let freeing ports to become blocked.
When at sea, never turn your vessel with any quantity of water on your deck.

You have to now the stability criteria for your vessel,
(1) Area under curve up to 30 degrees not less than 0.055 metres radians
(2) Area under curve up to 40 degrees not less than 0.09 metres radians
(3) Area between 30 and 40 degrees not less that 0.03 metres radians
(4) Maximum Gz to occur at an angle not less than 25 degrees but maximum Gz should occur at an angle exceeding 30 degrees
(5) Initial GM not less than 0.35 m for fishing vessels and 0.15 metres for merchant navy vessels
A radian equals 57.3 degree's