Re: New experiences!
Lacerations are by far the most common surfing injury requiring medical attention (ie not counting bruises and strains etc that you deal with on your own), with the head (board impact) and feet (fin impact or impact with something under the water) being the usual sites. I have read some studies (there are plenty on the internet) that the injury rate per surfing hour is the same regardless of the level of experience - so the risk of your board hitting you doesnt go away as you become a better surfer. When you wipe out you have absolutely no control over your board, it could land anywhere not matter how long you have been surfing (that said, of course, the risk of injury for a beginner on white water is far less than for someone on an 8ft reef break).
Apart from hands over the head, if you are able and feel confident in the conditions, another option is to stay underwater just for a couple of extra seconds to give the board time to land or even look around while underwater to see if you can spot the board. But this is not always possible and a following wave might pick the board up and slam it into your face anyway.
I do agree it is strange how opposed to helmets surfers are (or, really, apathetic to the issue), not that I wear one and that is after having thought about it. The Gath helmets seem designed to protect you against a big impact, like hitting your head against a rock, and just seem like 'overkill' for the standard beach break. I've always wondered whether its possible to built a lightweight helmet that will offer protection against surfboard impact but is not designed for the head against rock situation. Maybe something like a hat that has some kind of harder rubber (harder than just a hood); or a helmet isnt a full solid shell but, like some bike helmets, has gaps between the protective strips and is much ligher weight (plus easier to drain the water). Sure if a narrow nose hits you in between the strips it wont help, but usually you are hit by a part of the board larger than just the nose. Lacerations occur when hard surface (board) hits hard surface (skull) - all you need is something between those surfaces and it really helps in terms of lacerations (so getting 10 stiches while wearing a hoodie as well is an 'impressive' achievement). Surf lifesavers (eg in boats and paddling) would also possibly use it, something that has been raised in the unfortunate deaths of life saver competitors in Australia in the recent past.
Even with a Gath helmet you will still get concussion from an impact, so why not a helmet that is designed purely for board lacerations?
And, my personal view - I'm not convinced from a safety point of view about the standard rule of leg rope length being the length of the board. Why not board length plus 1ft or 2 ft? The further the board can get from you the less likely it is to hit you, and that extra 2ft isnt going to cause any other issues (ok, well, if you are very good you may notice the extra drag, but apart from those people). It would be interesting to see a study as to whether longboarders with 9 or 10ft leashes get hit more or less than shortboarders with 6ft leashes - recognising, of course, that being hit with a solid lump of a longboard probably feels less fun than being hit with a potato chip. Anyway, to answer your question and this is a totally subjective opinion, an 8ft leash on a 7ft3 is much better than a 7ft leash.