To be upset DGP's are taking DC on holiday?

I hear you OP.
I'm your parents age and wouldn't dream of just taking my GC away without first asking permission and giving a detailed itinerary.
It's not the same as having your own DC at all.
With your own DC you "have got your eye in" so to speak. You are used to constantly risk assessing through every waking hour.
If you aren't doing that every day you can lose the "sharpness".
Your own home is geared up for kids, a holiday home might not be. I remember my MIL letting our children get items out of her giant chest freezer, without a thought that they might fall in. The kettle cable dangling off the work surface!
She also didn't see the danger with her having a unfenced garden pond and only a partially fenced garden.
Talk to them OP. You are in charge.

OP, I was born in the 1960s. My grandparents were born in the early 1890s, so they were old by today's standards to be very involved , which they were. They took me and my brother all over the place with no accident happening and if (my grandmother especially) had been questioned about it, parents would have been handed their arse on a plate.

You either trust them to look after them or not and if you don't you shouldn't ask for childcare. They are not taking them off to be abandoned and cared for by wolves.

From the other point of view, my DP & I regularly look after 2 grandkids and often chose / decide to take them away for short breaks as it gives us plenty of things to do, we eat out so no meal prep and we come home to our house which remains clean & tidy.
I love having them but love my own life too. Their parents tell me their grateful we are giving the kids good experiences and are happy for us to do it we are lucky we can afford to spend the money on them. I've even booked last minute trip without asking parents first as it was a last minute offer and I chose to say yes and then tell parents.

i dont think you are being unreasonable to be upset the DGPs didnt ask you about taking your kids away. it would have been the right thing to do if looking after children to say,wed like to do a) when the kids are staying with us ,is that ok with you?
Having said that,do you object to whatever plans they have? if so,you ned to have a conversation ,if not,i'd let it go.

I cant see why they would have to ask permission when the children are planned to be with them anyway. It is a lovely idea.

I think your anxiety is partially coming because they didn'tt ask, and they know this is something you have felt anxious before and they still didn't check in. I wouldn't exactly like this either, I'd expect the plans for the weekend to be open and transparent and them to ask if taking the kids away was a good idea. That said, now you know, I think it would be fine if you trust them, I trust my mum to take my kids to the beach as she's an exceptional parent, but it does depend on the parents!

Not weird to want to be asked about children going several hours away on a mini-holiday when you thought they were staying local.

Unless they are completely incompetent, the risks are still going to be low.

If they’re babysitting for you they’re doing you a massive favour for the weekend and giving their GC a lovely time
I fail to see why you are upset about this!! Lots of people would love this - my kids have no grandparents they’ve all passed away but I’d love this how nice and kind and thoughtful!

If you trusted me to look after your children at your convenience, I would assume you trusted me to do normal everyday activities with them.

Well more than that though with water / pools/ beaches involved and 6/4 yr olds - I’d definitely be expecting a chat about it/ permission sought.

OP - trust your instincts; it doesn’t matter what anyone else thinks about it - they’re your children and you’re doing your job to protect them / ensure they’re safe and well.

Which is the wrong comparison because there was no reason to presume that's all they'd be doing. Mine would've asked about taking them away. But even if they weren't having a holiday, the GPs could be doing any and every kind of day trip. Beach included.

My kids are the same age OP. I trust my parents with my children and I know they wouldn’t take them away without checking with me. And I know they wouldn’t take them somewhere that they’d feel it’s out of their comfort zone, ie swimming in the pool they know they can manage, swimming in the sea, absolutely no (my mums words). I have a pool in my garden and when having children for a play date I always text the parent if they’re ok if their children go for a swim.
ignore comments saying if you trust your parents looking after the kids in their home you should trust them everywhere. It depends how old your parents are, how fit, can they keep up with the little ones all day, are they fit enough to sprint after a child if the child decides to run away.
my parents take my children to the parks, farms, shops etc. my MIL looks after them over the weekend but only in her house/garden because she’s approaching 80 so isn’t comfortable taking them anywhere. She’s completely shattered after the weekend with them without leaving the house but says she wants to help more. We ask only couple of times per year.
Only you know if your parents are capable to take your children away to the seaside. I wouldn’t be! And yes they should have asked!

YABU. If it's only a couple of hours away, would you be ok with them going to the beach for a day trip? What difference does it make of they stay overnight, especially as they will be having them in their care anyway

I have been taking my grandson roadtripping since he was 5. I just book him in advance like a table reservation 🤣 Parents are delighted that I take him off their hands for a while. I don't think they are particularly bothered where we go each day, they know roughly what part of the UK we are in. They get regular trip reports, photos and updates and are happy with that. All they care about is that he is safe in my charge and we are having an excellent time

I would expect to know where in the country my dc were and it is completely normal to speak with parents not just plan trips away. Anyone thinking this is an odd requirement is very strange.

You are happy to clear off on holiday and leave the kid behind but not happy if their grandparents do it?

I just can’t imagine not having the conversation with my daughter that I was taking them away somewhere. Mumsnet can be a bit off when someone is babysitting. But yes, of course it’s something you have a conversation about. If I’d suggested it and my DD said, “oh I think they’re a bit young” or “DGS is a bit iffy with bust roads” or anything at all, or even just wasn’t ok with it then I’d respect that and either suggest a day trip or keep it low key. I’m sure they did it as a treat, but when you’ve booked a probably long awaited trip you just want to know that the kids are somewhere familiar and safe.
I get it OP.
Are you going to have a chat with them?

I have a 5yr old (just) and would feel the same as you. Bit young really; would be easier / safer (and you’d feel more confident about it all) if the GPs looked after them at your/ their home rather than away in a new place. I get it. I’d actually ask if they can reconsider the location tbh as it doesn’t sit right.

There will be crowds of people in local parks etc because it is the summer holidays, busier local roads to cross etc risks are still there if staying local too, especially if not supervised correctly.

If supervised correctly then the risks are going to be low no matter where they are.

I voted YABU but actually I think YANBU.
I didn’t realise your children are very young.
looking after two smalls at a busy beach and in the sea is a lot of work in terms of keeping them safe. Certainly it would be too much for my parents. Yours may be fitter/younger.

YANBU

They’re already minding the children for the weekend regardless. They haven’t booked a trip and just assumed you would let the DC go, the DC were already in their care so I really don’t get the big deal.