Hello younggun, a few points to be aware -of. You surf daily... salt water is harsh on any system hair [ it`s harsh enough on growing hair, let alone non-growing ] so I feel that will certainly affect how much wear you get. A fullcap has the advantage that you don`t have the bother of blending it in with growing hair and you just keep your head shaved yourself..... irrespective of full or partial, lace is totally comfortable...... with an active lifestyle, I wouldn`t recommend an all -poly system especially as you have a skin condition as it is ...the build-up of sweat etc under an all- poly would probably make things worse. I`m not a dermatologist but I know that Coal -tar shampoos can be extremely soothing on the scalp and `calm`things down... I don`t know what country you are in, but try Neutragena T-gel shampoo ....it`s widely available in Ireland, so I assume it`s available freely elsewhere.... or just go to your Pharmacy and ask for a shampoo based on coal tar......it`s a bit expensive but very effective on many skin conditions. I would NOT recommend going to a normal salon wearing a system and `hope for the best` ... the stylist working at such close quarters will eventually spot the system when the hair is damp, and also, even if he/she didn`t, it`s quite possible that the relatively sharp tips of a comb will catch/snag in the lace and result in a rip. You certainly could go, but tell them you are wearing...all they have to do is `lift`the system hair upwards allowing access to the growing hair.....shouldn`t be an issue for any stylist.
If you can get away without a full -cap for now, try a partial which you will find a little easier to `work`with, regarding getting used to attachments because I reckon you will have to do more frequent de/re- bonds in order to maintain/clean the hair due to exposure to salt water.
There is no reason you couldn`t wear per se, just don`t expect too much from a system if it`s going to be exposed to a lot of `harsh wear`....... regards, Paul.