Here is some rental information found on Castle Comfort's website. I have put Babykorms on the list for a Cochran as well.
Rental equipment
Regulator and gauges $10 per day
BCD $10 per day
Mask, fins and snorkel $10 per day
Shortie wet suit $14 per day
Dive light $14 per day
Dive computer $14 per day
Rental prices are quoted in US $ and exclude local VAT tax (10%).
Dive prices exclude Soufriere Scotts Head Marine Reserve fees of $2 per person per tank.
Dive prices are per person and may be subject to change.