This time I will be serious. (I can be when need to).
I read Sail's post, and all subsequent ones. (I needed T's help with some meanings, thanks T).
Opening a hatch or a port for sail handling or light is a common thing today and is required, however it needs to be done properly.
Here some points:
One is that today, boats without light inside don't sell, look at the raise in numbers of deck saloons and other large deck houses surrounded by windows produced today. There is a trend there. Unfortunately, the larger the hole, the weaker the structural integrity of the surrounding structure. Add that to the decrease in construction performance, to decrease production costs and the ingredients are right for catastrophe.
Second the hatch construction itself. There are several types of hatches and they have to respect certain codes (Lewmar I know does), because when deciding on my hatches we were offered a multitude of hatches that went from light less resistant to slim line for aerodynamic qualities to oceanic types. Unfortunately, the most expensive are the oceanic (due to heavier materials and type of construction) and the aerodynamic, due to their cost in research. In parallel, you may acquire a hatch that fits the job, at a lesser cost, but not suitable for oceanic conditions. Albeit the weight, I decided on oceanic hatches, mainly for safety, but also because they will take more abuse. I had however a 45% increase in cost due to that. And I only built one boat, Imagine production houses that build 60 or more.
Third we have the rules of each Country. Over here, you have a minimum requirements as far as hatches and ports go, to prevent bad quality and construction, however, it does not cover replacements and modifications. And I know that some production get away from this…..
In my particular case, we had to reinforce (and they inspected it) the cabins structure around the hatch to satisfy the inspectors, but I know that many builders here and there do not do this. I don’t believe that what will fail is the cabin structure, but the hatch itself.
Initially, my boat was going to have nice hull windows and we soon decided, absolutely not. The boat will race, will hit pontoons, other boats etc, and even on a cruising boat, the occasional “love rub” in inevitable, then water starts getting in.
As far as procedures to improvise and cover a hatch hole. I think you may hit a good point. As far as I know, there are none here for oceanic passages. I know however, that a friend that sailed to Macau, decided to cover one of his ports and had makeshift boards to cover the hatches form the inside.
So at the end of the day, we are relying in one’s experience and seamanship to succeed and cover all bases for maximum safety.
Truth is, if one of my hatches goes, and the weather hits, I am done. So after this, I am going to make wood plates for my hatches, just in case.
Very very good point here Sail.