How fast is he planning?! This makes a big big difference! My Dad will be around 5 hours and we aim to see him 4-5 times (have successfully achieved this previously!). Sub 4 and you need to be much more cautious.
Make or get a distinctive sign or balloon or get a megaphone or something. It’d SO hard to pick out faces in the crowd whilst running so make yourselves as visible as possible!
We usually walk down from North Greenwich tube to the route for Mile 6- it’s very quiet as it’s a bit of a walk!
Posters advising using the Greenwich foot tunnel. Beware! The last few years it’s been closed and this year I believe is south bound only!
Work out his target time and minute mile pace. Once you know this you can do the maths. So my Dad is aiming for 10 min miles, meaning we have 60 minutes to get between miles 6 and 12. This will help you work out if you are on track for example if you get stuck in a massive tube queue.
Utilise spots where you can see a runner twice:
Canada Water is a busy tube but you can jump between miles 9 and 11 and see your runner twice.
Canary Wharf is usually worth the queue because you can see a runner at mile 15 and again at 18 without moving very far yourself. HOWEVER despite it only being 1 tube stop the queues will mean you can’t do both of these so pick one!
On the mile 14/22 combo, yes this a good one but beware that it’s a 2 way street so on the first go you might just be yelling from across the street past all the faster runners so people can’t always see you!
I always like Embankment around miles 23/24 the side furthest from the river- there are some quieter spots so it’s easy to get to the front and easier for your runner to spot you. You can walk to the finish from here really.
You should also know that there will be absolutely zero phone signal at the finish! Follow the London Marathon advice to pick a letter to meet under and absolutely do not deviate from this plan! Some people advise going straight to the charity reception and meeting there instead but I always like to meet my DH earlier so he can carry my bag 😂.
Spectating can be really tiring too, I’ve clocked up 30k steps cheering in London before! Wear comfy trainers and take snacks and drinks in a backpack as you won’t get anywhere near any shops or cafes, there will be too many crowds and queues!
It is a really magical once in a lifetime experience so best of luck to your DH!