To improve the efficiency of your staff on deck you have the choice to implement our touch based interface where the staff account can perform most of their daily tasks.
We have two specific recommendations - One economic but efficient solution and one perfect solution. Overall we recommend a 7" version of any tablet as this can handle all tasks and is not as prone to dropping due to better grip.
For a price as low as $100-150 (2018) you get a super efficient tool at a cost that will not ruin you even if it breaks (or gets stolen). We have better experience with the brands ASUS, Lenovo and Dell and over-all we recommend you to stear clear of 'no-name' brands. You can further improve ruggedness by using a cheap waterproof cover.
If you want the best tool for the job you pay the $1.000 (early 2013) and get a tablet that easily handles the wet environment, dropping and anything else you throw at it.