Never got charged at Scrub for day tripping (last time 2 weeks ago ferried from Tola). As long as you drink/eat at the pool, bring your own towel, no worries. Have not been at the Bitter End for a while, but usually the pool fee (10-15/day) includes towels, lounge usage and the fee is deducted from your lunch bill. Drinks, however, are a bit pricey.