Originally Posted by Ann T. Cate
The perspex inserts to reduce condensation and heat loss are brilliant! Lovely idea.
I'm still not understanding how these hatches will allow good ventilation underway when it's blowy....... Please explain.
Ann, thanks for your concern about ventilation. I agree it is a very underrated area. Ventilation not only when sailing, but at anchor
and when storing the boat needs to be considered.
Ventilation at anchor is the most important. On hot nights it is critical for comfort to get enough airflow over the sleeping area. This requires big, well placed hatches with cross ventilation.
Unfortunately, few boats can leave these hatches open in even light rain. There are some features on this new boat that will help enable this:
The hatches will be on 50mm plinth. Standing water on the deck has to get over this level to enter the hatch.
There will be welded loops around the hatch for a Sunbrella wind scoop/rain guard/spray guard.
Here are some photos showing examples of Sunbrella awnings that boat owners have constructed, but it is difficult to fabricate these for conventional boat hatches. With the welded attachment points around our hatches and raised plinth we will be able to make something that is smaller and neater, as well as a lot more water and wind proof than these examples that mostly rely on the lifelines
for the attachment points. SWL is great with canvas
work so she can make these.
We could also use something similar for all the other hatches, but the pilot house hatches (two 500x500) will be covered by the boom tent at anchor, which will protect them from rain unless the wind is strong.
I am confident airflow at anchor particularly when raining will be much better than most boats.
When sailing I am not convinced that the small token dorades often fitted do much, but we are making some conscious compromises leaving off proper large sized dorades. Anyone who has sailed knows the danger
of leaving hatches open only to have a larger than normal wave soak the interior
. It is mistake you only make once
The pilot house washboards slide up and down in their own recess. They can be raised and left in any position. They are protected by a large aluminium overhang. That creates a mini doghouse. Primarily this provides a place to shelter outside from spray and wind, but it also protects the pilothouse from rain/spray. With the washboards partially raised there is ventilation that is unlikely to get any water entry. I think this will provide reasonable ventilation offshore
, especially as the pilot house will be the most used area of the boat when sailing.
This photo of a Bestevaer 49 under construction shows the the size of the overhang at the rear of the pilothouse:
The high plinth around the hatches will make them a bit more practical to open in mild conditions, particularly the pilot house hatches which are a long way above the waterline. A Sunbrella spray shield would help even further.
When the boat is stored/unattended:
There will be two sliding self stowing washboards. The first will have a security grill
, fly screen
and a very strong lock. The second will be conventional clear Lexan
. They can be used individually or together.
When leaving the boat for extended periods at a marina or on the hard
, it will be possible to lock the security grill
closed, but leave a small air gap at the top of the plastic washboard. The aluminium doghouse roof should ensure that no rain gets in.
With the absence of leaks
and thick insulation
, aluminium boats stay very dry. This, coupled with all the above should be enough to keep the boat fresh. I think dorades will not be missed.