The USCG Physical is very similar to DOT Physical from my understanding. I'd recommend you have a look at the actual form. I've heard you can get waivers for just about anything. The form is CG-719K. From my understanding your primary care can fill out the form but I actually had mine done at Doctor's Express since I didn't want to wait for an appointment. There are also places that specialize (or are at least more familiar with USCG physical)
Some good reading here..
https://www.uscg.mil/nmc/credentials/forms/cg719k_instruction_guide.pdf
https://www.uscg.mil/forms/cg/CG_719K.pdf
https://www.uscg.mil/hq/cg5/nvic/pdf/2008/NVIC_04-08_CH2.pdf
Big things they check, blood pressure, hearing, vision (color, field of vision, uncorrected/corrected)
Page 6 Section V(a) - Visual Acuity:
The VMP must complete the mariner’s Visual Acuity. If any block is marked “Abnormal”, information should accompany the CG 719K to explain. For applicants using corrective lenses, the VMP must include both uncorrected and corrected distant vision testing. Current deck standards require an applicant to have correctable vision to at least 20/40 in one eye and uncorrected vision of at least 20/200 in the same eye. Current engineering, radio operator, tankerman and MODU standards require an applicant to have correctable vision of at least 20/50 in one eye and uncorrected vision of at least 20/200 in the same eye. See NVIC 04-08 encl (5) for further guidance.
Section V(b) - Color vision:
Current regulations require all applicants to submit the results of color vision testing. The color vision test performed should be selected from the list provided, and the 719K must be checked normal or abnormal. If any block is checked “Abnormal”, information must accompany the CG 719K to explain. Any alternative test must be approved by the USCG prior to sending the examination report. The use of unapproved alternative testing will likely cause delays in the medical evaluation process. The use of color sensing lenses is prohibited. See NVIC 04-08 encl (5) for further guidance.
Section VI: - Hearing:
It is not necessary to submit an audiogram for an applicant with normal hearing. If hearing is abnormal, the applicant must submit the results of audiogram testing to include functional speech discrimination at 55dB. The frequency responses for each ear are averaged to determine the measure of an applicant’s hearing ability. Current regulations have changed the hearing standard from 30dB average at 500 Hz, 1000Hz, 2000Hz and 3000Hz to 20dB in each ear. See NVIC 04-08 encl (5) for further guidance.