Trying to see which requirements to go by when wiring a heater for a baptismal pool. It's going to have a 240 outlet that the heater plugs into. The heater is wall mount and has a cord on it with controls etc. I know it has to be GFCI protected. If it can be considered the same as a spa or hot tub, the cord can be up to 15 ft. long according to 680.42 (2). I guess the outlet would still have to be at least 6 ft. from the inside walls and any switch or disconnect would have to be at least 5 ft. from the inside walls. Cord on heater would have to be rated "hard usage". Any more thoughts on this?

sparkync:
Sounds like you have it covered. A baptismal pool falls into the 'immersion pool' area of the NEC, of which IMHO there is little to read.

My question is this heater is to heat the water? Is there any circulation pump?

Depending on your local AHJ, he may want a EPO switch to kill the heater & circ pump.

No pump at all. Just a portable heat unit that sets in the water till it's heated then removed. Pool is drained after use.

IMHO, go with what you described in your original post.