Below are two suggestions for summer training. There is no reason you cannot do any other plan, just as long as it is consistent, and has a purpose.
The more you can gain over this summer, the better your personal best will be next season.
Strength Program - Here
Endurance Program - Here
Ideally 6 days a week alternating strength and endurance. Stretch before and after each training session and also twice on the rest day.
If you have any other questions let me know.
Keep you goals in mind when you are training, and keep the quality high.
Rowing is classed as a power endurance sport, meaning you need to produce a pretty large amount of power over a time of 5-8 minutes (in the spring), and 20 minutes in the fall.
Basic endurance training means approximately 80-90 minutes of continuous work at a heart rate of 150-160 beats per minute. You can do one exercise the whole time, or break it up into different activities to keep it from getting too boring. Examples: Rowing, erging, running, biking, swiming, basketball, tennis, etc. The main thing is to keep moving.
Power/Strength work needs to be resistance training of some sort. Higher weight/resistance and lower reps/rate.
Muscular endurance work of body or weight circuits. Lower weight and higher reps.
Winter Training Handout: Click here.
The Erg Information above was from Fletcher Sport Science (UK). A useful site.