Yes, I don't have to understand . . . but I'd like to. (And I don't require anyone to explain.) Understanding is why most of us frequent forums like this, no? I would think someone as intellectually curious as you seem to be would agree.
Ok,well I'll have a go at helping your understanding in this matter, just for the 'fun' of it Angus.
1. My boat has a flybridge, but even here in the Queensland, subtropical weather we find it either too hot up there in summer, or not that great in winter sailing. Certainly horrible in a seaway of any sort.
2. The lines of a boat are usually not improved by them. Some might, but most effective feature for better visibility in all weathers, in my view & many others I suspect, is when there is a raised pilot house. In which case, I feel the flybridge stuck up above is rendered superfluous, as long as the P/H has a door each side, and preferably (in a larger vessel), a Portuguese bridge around it.
3. It is costly having to duplicate each and every instrument and nav aid up there, but if you don't, then you are at a disadvantage. And Marin's suspicions re warning devices have some validity.
4. The heat encountered up there if said instruments are protected from the weather by enclosures, is so hot and steamy it shortens their life anyway. Believe me, I know this...
5. The said enclosures cause added height (bridges etc), weight, and windage, so even if you just leave them closed and ignore them if you don't like them, (as you suggested in one post), they are still
there, causing the above...and one more negative as below...
6. they are a common cause of water ingress - how do I know - because I'm currently (with the boat up for sale), having a devil of a job finding how and where water is getting in somewhere on the bridge deck, and for the first time ever, (Murphy's Law), sometimes actually leaking inside - something never experienced before this year. Without the damn flybridge the upper deck would just be an uncluttered, and easily water (re)- proofed rooftop..., oh, and ...
7. therefore supplying lots of nice extra space for solar panels...
The only time we have found it quite useful in fact, was watching the fireworks at New Year, and how often does that come around?
Does that help in your understanding at all..?
PS.
Hey Heals, if you're there and see this, would you have a go at taking my flybridge off. Then I'd have one with wannabe windows and one sans flybridge...