Outside lighting and cable run around a lake

Hi Folks, I am working on a fishery with a house on it that will be air B+B’d. The client wants outside lighting all around the property, front and rear. 3 of the circuits will be running around two lakes. There is a lot of trees, roots and obstacles, so the client does not want to dig trenches to run the cables underground. I am going to use either wise box’s or Shelly Pro 3’s to control all the circuits. The feeds to each control will be trenched, it is just the load runs that cannot be trenched. 
Could anyone help advise me on the running of cables around the lakes. I would like to run the cable in SWA, but as it is a commercial let property I am in a quandary over best practice and regs/ safety. Many thanks. Regards Giles 

    • Thank you all for your replies. All very helpful and welcome. I am still undecided as to what will do with this quote and this job. There is a fine line between getting the client what they want at a cost they can afford and covering all the problems and safety guidelines that come with laying the cable on this type of job. It is a large lighting design with multiple zones and 2 or more circuits off those zones..Again many thanks for all your input.. Regards Giles