Excellent, thanks again!

@ Smokeybear and krlyr - Do you two live on here?

He'll be down the beach at the weekend, so no doubt plenty of dogs and hopefully he will learn to swim!!!

He will become a good dog, I know it, especially as I have the time to put into him. Perseverance, I guess!

Totally agree with Krlyr about sticking to the exercise limits and not over exercising at this age. Swimming is a very good exercise which is not stressful on the joints A good 10 min clicker session will stretch the brain and can be surprisingly tiring. All try puzzle toys like a Buster cube or freeze food in Kong to work his mind and keep him quiet

I'm not massively experienced but I do have a GSDx dog who was under socialised as a puppy and the resulting, fear aggressive dog is not much fun to walk! At his age it's much better to tackle it now. I would be surprised if it's true aggression at his age, probably a mix of frustration at wanting to play and some GSD gobbiness due to lack of confidence. While obviously not letting aggression actually happen, I would seriously look into befriending dog owners in the area and socialising him as much as possibly with appropriate dogs (calm, friendly, playful but not OTT, and ideally do not react to his gobbiness). Try to avoid any bad experiences, he's does not need putting in his place by other dogs as that can cause more fear, he needs guiding and teaching how to socialise. These dogs aren't always easy to find, but if you tackle this now you will make your life a lot easier later!

Good luck, I sympathise with you and as said by others, you are not alone! Thr good thing is that he is young enough to turn around

Re: the barking thing, taking him inside should work great. I found if I shouted at Cain he thought I was joining in and carried on louder! Now I call him away from the window in a very soft voice, click and treat and that stopped him. Now I don't need to treat, I just say "enough" very softly and he stops, works much better than shouting. You could also train him to "speak" on command, and quiet so he has an outlet for barking when allowed but also an off switch!