Hi. My name is*****'m looking at your question now and will post my answer or ask for more information here in a short while.
Your Panama earnings will be taxable in the UK as you will continue to be treated as tax resident in the UK so split year treatment is irrelevant. The bare minimum you have to achieve to avoid UK tax on foreign earnings is to spend at least one complete tax year (6 April to 5 April) as a UK non-resident. You won't do that based on the period you are scheduled to be abroad.
I hope this clarifies things for you but let me know if you have any further questions.
Hi.I'm just following up to find out if my answer helped or if you have any further questions.