I completely misread what you said about swimming Tiggerella sorry! - and yes I'm using an Insight same as you.
Algorithms are the computer progs they use to calculate stuff (like when the hansdet works out what bolus we need from our current BG and amount of carbs we tell it.)
The Roche software supplied to the clinics has a section on it where they enter the patient details, and it calculates the suggested hour by hour base rate of insulin. If the clinician and you the patient agree they look sensible they then connect the handset to the puter, and it copies the rates on the screen onto the pump. I assumed that was what you meant when you said your basal rates 'were worked out for me' - if it isn't and it was done manually like they always had to be originally by you and your DSN (like when I had my Combo before the Insight) they might have a better chance of being about right, cos you already know to some extent what happens to your BG when - but the rates never stay completely unaltered for all that long, in any case.
But anyway when you very first get your pump, after a fortnight with it my clinic ask you to do at least one full 24 hours of basal testing and expect us to do that anyway at intervals or as and when required so any adjustments we haven't already tried ourselves can be spotted and implemented. Dunno if every clinic's the same though. I hardly ever check back with my clinic anyway - just change things myself as necessary. Hospital pick the changes up at the next visit whenever that happens cos the software automatically updates it when they download it.