I can tell you something about Shrewsbury. Admittedly the information will be about 4 years out of date, and there has been a change in head in that time. But I'll tell you what I know! Might be long, sorry!
Definitely a full boarding school -no mass exodus on the weekend which would be great for you. But willing to let overseas pupils leave a day or so early if needs be to get home at the end of term (which I know with flight costs can be a great thing!)
Shrewsbury only started taking girls in 2008, and that was in Sixth Form only. From this September they will start taking girls all the way through (I'll keep my thoughts on that to myself since it's not really relevant given your daughter's age!). What it does mean is that in Sixth Form you get a fresh new cohort of girls, so no long-standing existing friendships to break into which I know some people worry about when joining a school at Sixth Form. Also because you're joining at 16, you're treated very much as a young adult and I think that's great preparation for university and life!
Academics - the ethos is very much about getting every child to achieve their potential. So for a school that isn't super-academically selective, they get a good number into Oxbridge each year (if that's a measure you want to use!). Lots of support both in problem areas, but also in pushing DC further than the curriculum if that's what they want / need. Very enthusiastic teachers, who really embrace life at a boarding school. They run the Cambridge Pre-U as a replacement or alternative to A Levels in some subjects, which is seen as a good academic challenge qualification.
Boarding - the girls' boarding houses are lovely and new. Sharing rooms in first year (2s or 3s), then singles in Upper Sixth (with en suites in one house). Sixth Formers are allowed into town on a Saturday evening for a meal out (have to sign back in at a certain time). There's (I presume it still exists) a Sixth Form bar on site, where Sixth Formers are allowed to buy a limited number of set alcoholic drinks with parental permission on a Saturday night (beer/cider/alcopops/wine). Personally I believe it's a great controlled way to give 16/17/18 year olds a bit more independence and responsibility.
Pastoral care is great; good house boarding teams, as well as a personal tutor which the students pick themselves.
Sport - no sailing as far as I am aware. But there is a scuba diving club. Students have Thursday afternoons off lessons which is time used for structured extra-curricular activities, of which scuba diving is one. Wonderful swimming pool. Very strong rowing school - so perhaps a new watersports opportunity?! Plus all the usual school sports.
This has been really long - sorry!
What I will say is that a Shrewsbury girl needs to be confident and resilient. I feel the girls very much adapted to the Shrewsbury boys' way of life, rather than making huge changes to the ethos of the school. To me, that's a great thing but might not suit all girls.
Ultimately visiting schools helps so much in making decisions, but I know that's hard from abroad! Sometimes you'll just walk around a school and know it's right, or not, for you!
Please ask me any more questions, or PM if you'd prefer!