Most boats that come from the factory consider that the tanks
would be filled at some point and you would carry normal gear
. The only time you should have a problem is when you install heavy items or decide to expand tankage.
Something like a large genset at the factory might have appropriate ballast removed to account for the extra weight, If you are just filling the lockers as full as possible you'll need to feel secure that you boat has sufficient displacement
. Many cruising boats are designed from the get go with this in mind. The "heavy cruiser' carries more stuff! In serious weather
it all matter most of all.
If you want to strap and extra 60 gallons of fuel
some place or carry an extra 25 gallons of water you may need to adjust for the trim of the boat and of course anything heavy needs to be very secure as in "can't come loose in a knock down" type secure. Heavy objects loose in a knock down could be fatal for the boat or a crew member
. Consider a heavy object that weight as much as a brick flying past your head
. Now imagine a group 4 battery
. Even a few pounds in flight can lay some hurt on you or worse drive a hole in something or at the very least destroy itself on impact.
You'll want to avoid overloading the stern or bow and attempt to get the heavy stuff as low as possible. Note your water line before you start loading and again after to see what you have done.